NELLCOR INC /DE/
S-4/A, 1995-07-21
ELECTROMEDICAL & ELECTROTHERAPEUTIC APPARATUS
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<PAGE>
   
     AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON JULY 21, 1995
    
   
                                                       REGISTRATION NO. 33-61169
    
- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                           --------------------------

   
                                AMENDMENT NO. 1
                                       TO
                                    FORM S-4
    
                             REGISTRATION STATEMENT
                                     UNDER
                           THE SECURITIES ACT OF 1933
                            ------------------------

                              NELLCOR INCORPORATED
             (Exact name of registrant as specified in its charter)

<TABLE>
<S>                                     <C>                                     <C>
               DELAWARE                                  3845                                 94-2789249
     (State or other jurisdiction                 (Primary Standard                        (I.R.S. Employer
  of incorporation or organization)                   Industrial                        Identification Number)
                                             Classification Code Number)
</TABLE>

                              4280 HACIENDA DRIVE
                          PLEASANTON, CALIFORNIA 94588
                                 (510) 463-4000
                  (Address, including zip code, and telephone
                        number, including area code, of
                   registrant's principal executive offices)

                             LAUREEN DEBUONO, ESQ.
                   EXECUTIVE VICE PRESIDENT, HUMAN RESOURCES,
                         GENERAL COUNSEL AND SECRETARY
                              4280 HACIENDA DRIVE
                          PLEASANTON, CALIFORNIA 94588
                                 (510) 463-4000
                    (Name, address, including zip code, and
                     telephone number, including area code,
                             of agent for service)
                           --------------------------

<TABLE>
<S>                                                      <C>
                                                   COPIES TO:
                 GAVIN B. GROVER, ESQ.                                    DANIEL C. WEARY, ESQ.
               C. PATRICK MACHADO, ESQ.                                 JEFFREY T. HAUGHEY, ESQ.
               MICHAEL G. O'BRYAN, ESQ.                             BLACKWELL SANDERS MATHENY WEARY &
                  MORRISON & FOERSTER                                         LOMBARDI L.C.
                 345 CALIFORNIA STREET                                2300 MAIN STREET, SUITE 1100
            SAN FRANCISCO, CALIFORNIA 94104                            KANSAS CITY, MISSOURI 64108
                    (415) 677-7000                                           (816) 274-6800
</TABLE>

                           --------------------------

          APPROXIMATE DATE OF COMMENCEMENT OF PROPOSED SALE TO THE PUBLIC:
  AS SOON AS PRACTICABLE AFTER THIS REGISTRATION STATEMENT BECOMES EFFECTIVE.

    If  the  securities being  registered  on this  Form  are to  be  offered in
connection with the formation of a holding company and there is compliance  with
General Instruction G, check the following box. / /
                           --------------------------

   
    THE  REGISTRANT HEREBY  AMENDS THIS REGISTRATION  STATEMENT ON  SUCH DATE OR
DATES AS MAY BE NECESSARY TO DELAY ITS EFFECTIVE DATE UNTIL THE REGISTRANT SHALL
FILE A  FURTHER  AMENDMENT  WHICH SPECIFICALLY  STATES  THAT  THIS  REGISTRATION
STATEMENT  SHALL THEREAFTER BECOME EFFECTIVE IN  ACCORDANCE WITH SECTION 8(A) OF
THE SECURITIES ACT  OF 1933  OR UNTIL  THE REGISTRATION  STATEMENT SHALL  BECOME
EFFECTIVE  ON SUCH DATE AS THE COMMISSION, ACTING PURSUANT TO SAID SECTION 8(A),
MAY DETERMINE.
    

- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
<PAGE>
                              NELLCOR INCORPORATED
                             CROSS REFERENCE SHEET
             BETWEEN ITEMS IN PART I OF THE REGISTRATION STATEMENT
               (FORM S-4) AND PROSPECTUS PURSUANT TO ITEM 501(B)

<TABLE>
<CAPTION>
                                 ITEM OF FORM S-4                                       LOCATION IN PROSPECTUS
           -------------------------------------------------------------  --------------------------------------------------
<S>        <C>        <C>                                                 <C>
A.  INFORMATION ABOUT THE
     TRANSACTION
                  1.  Forepart of Registration Statement and Outside
                       Front Cover Page of Prospectus...................  Outside Front Cover Page of Prospectus
                  2.  Inside Front and Outside Back Cover Pages of
                       Prospectus.......................................  Outside Front Cover Page of Prospectus; Available
                                                                           Information; Incorporation of Documents by
                                                                           Reference; Table of Contents
                  3.  Risk Factors, Ratio of Earnings to Fixed Charges
                       and Other Information............................  Outside Front Cover Page of Prospectus; Summary;
                                                                           Investment Considerations
                  4.  Terms of the Transaction..........................  Outside Front Cover Page of Prospectus; Summary;
                                                                           The Nellcor Special Meeting; The P-B Special
                                                                           Meeting; The Merger; The Merger Agreement;
                                                                           Management of Nellcor After the Merger;
                                                                           Description of Capital Stock of Nellcor;
                                                                           Comparison of Stockholder Rights
                  5.  Pro Forma Financial Information...................  Summary; Unaudited Pro Forma Combined Condensed
                                                                           Financial Statements
                  6.  Material Contracts with the Company Being
                       Acquired.........................................  The Merger; The Merger Agreement
                  7.  Additional Information Required for Reoffering by
                       Persons and Parties Deemed to be Underwriters....                          *
                  8.  Interests of Named Experts and Counsel............                          *
                  9.  Disclosure of Commission Position on
                       Indemnification for Securities Act Liabilities...                          *

B.  INFORMATION ABOUT THE
     REGISTRANT
                 10.  Information with Respect to S-3 Registrants.......                          *
                 11.  Incorporation of Certain Information by
                       Reference........................................  Available Information; Incorporation of Documents
                                                                           by Reference
                 12.  Information with Respect to S-2 or S-3
                       Registrants......................................                          *
                 13.  Incorporation of Certain Information by
                       Reference........................................                          *
                 14.  Information with Respect to Registrants Other Than
                       S-3 or S-2 Registrants...........................                          *
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
                                 ITEM OF FORM S-4                                       LOCATION IN PROSPECTUS
           -------------------------------------------------------------  --------------------------------------------------
C.  INFORMATION ABOUT THE COMPANY
     BEING ACQUIRED
<S>        <C>        <C>                                                 <C>
                 15.  Information with Respect to S-3 Companies.........                          *
                 16.  Information with Respect to S-2 or S-3
                       Companies........................................                          *
                 17.  Information with Respect to Companies Other Than
                       S-3 or S-2 Companies.............................                          *

D.  VOTING AND MANAGEMENT
     INFORMATION
                 18.  Information if Proxies, Consents or Authorizations
                       are to be Solicited..............................  Incorporation of Documents by Reference; Summary;
                                                                           The Nellcor Special Meeting; The P-B Special
                                                                           Meeting; The Merger; The Merger Agreement;
                                                                           Management of Nellcor After the Merger;
                                                                           Compensation of Directors and Certain Executive
                                                                           Officers of Nellcor; Beneficial Owners of Nellcor
                                                                           Common Stock; Stockholder Proposals
                 19.  Information if Proxies, Consents or Authorizations
                       are not to be Solicited or in an Exchange
                       Offer............................................                          *
<FN>
- ------------------------
*Not applicable or answer is negative.
</TABLE>
<PAGE>
                              [NELLCOR LETTERHEAD]

                                                                   July 24, 1995

Dear Stockholder:

    You  are cordially invited to attend  the Special Meeting of Stockholders of
Nellcor Incorporated ("Nellcor") to be held at 10:00 A.M. on August 24, 1995  at
the offices of Nellcor, 4280 Hacienda Drive, Pleasanton, California 94588.

    At  the Special  Meeting, you will  be asked  to consider and  vote upon the
following proposals:

    1.  To approve the issuance of  Nellcor Common Stock in connection with  the
       Agreement  and Plan of Merger, dated as of May 21, 1995 and amended as of
       June 30, 1995 (as amended,  the "Merger Agreement"), among Nellcor,  Puma
       Merger  Corporation, a Delaware corporation and a wholly-owned subsidiary
       of Nellcor ("Sub"), and Puritan-Bennett Corporation ("P-B"), pursuant  to
       which  Sub will be merged (the "Merger")  with and into P-B, and P-B will
       become  a  wholly-owned  subsidiary  of  Nellcor.  In  the  Merger,  each
       outstanding  share of  P-B Common  Stock (other  than shares  held in the
       treasury of P-B, which will be canceled) will be converted into the right
       to receive 0.88 of a fully paid and nonassessable share of Nellcor Common
       Stock. Cash will be delivered in lieu of fractional shares.

    2.  To approve an amendment to the Restated Certificate of Incorporation  of
       Nellcor  to change  Nellcor's corporate  name to  Nellcor Puritan Bennett
       Incorporated.

    3.  To approve  the adoption of Nellcor's  1995 Merger Stock Incentive  Plan
       (the "1995 Plan").

    4.    To approve  the  adoption of  an  amendment to  Nellcor's  1994 Equity
       Incentive Plan to increase the number  of shares of Nellcor Common  Stock
       authorized  for issuance  thereunder from  1,500,000 shares  to 2,500,000
       shares (the "1994 Plan Amendment").

    At the Special Meeting, you may also be asked to consider and vote upon such
other business as may properly come  before the meeting or any postponements  or
adjournments thereof.

    YOUR  BOARD  HAS UNANIMOUSLY  APPROVED THE  TERMS  OF THE  MERGER AGREEMENT,
BELIEVES THAT THE TERMS  OF THE MERGER  AGREEMENT ARE FAIR TO,  AND IN THE  BEST
INTERESTS  OF,  NELLCOR AND  ITS STOCKHOLDERS,  AND UNANIMOUSLY  RECOMMENDS THAT
HOLDERS OF SHARES OF NELLCOR COMMON STOCK VOTE "FOR" APPROVAL OF THE ISSUANCE OF
NELLCOR COMMON STOCK PURSUANT TO THE MERGER AGREEMENT, THE PROPOSED AMENDMENT TO
NELLCOR'S RESTATED CERTIFICATE OF  INCORPORATION, AND THE  ADOPTION OF THE  1995
PLAN AND THE 1994 PLAN AMENDMENT.

    The   accompanying  Joint   Proxy  Statement/Prospectus   provides  detailed
information concerning the proposed Merger and additional information concerning
Nellcor and P-B, which  you are urged  to read carefully.  It is important  that
your  shares  of Nellcor  Common Stock  be represented  at the  Special Meeting,
regardless of the number  of shares you hold.  Therefore, please sign, date  and
return  your proxy card as  soon as possible, whether or  not you plan to attend
the Special Meeting. This will not prevent you from voting your shares in person
if you subsequently choose to attend the Special Meeting.

                                          On behalf of the Board of Directors,

                                          C. Raymond Larkin, Jr.
                                          PRESIDENT AND CHIEF EXECUTIVE OFFICER
<PAGE>
                              NELLCOR INCORPORATED
                              4280 HACIENDA DRIVE
                          PLEASANTON, CALIFORNIA 94588

                            ------------------------

                   NOTICE OF SPECIAL MEETING OF STOCKHOLDERS
                           TO BE HELD AUGUST 24, 1995

                            ------------------------

To the Stockholders of Nellcor Incorporated:

    A Special  Meeting  of  Stockholders of  Nellcor  Incorporated,  a  Delaware
corporation  ("Nellcor"), will be held at 10:00  A.M. on August 24, 1995, at the
offices of Nellcor, 4280 Hacienda  Drive, Pleasanton, California 94588, for  the
following purposes:

    1.    To  consider approval  of  the  issuance of  Nellcor  Common  Stock in
       connection with the  Agreement and Plan  of Merger, dated  as of May  21,
       1995   and  amended  as  of  June  30,  1995  (as  amended,  the  "Merger
       Agreement"),  among  Nellcor,   Puma  Merger   Corporation,  a   Delaware
       corporation  and  a  wholly-owned  subsidiary  of  Nellcor  ("Sub"),  and
       Puritan-Bennett Corporation, a Delaware corporation ("P-B"), pursuant  to
       which  Sub will be merged (the "Merger")  with and into P-B, and P-B will
       become  a  wholly-owned  subsidiary  of  Nellcor.  In  the  Merger,  each
       outstanding  share of  P-B Common  Stock (other  than shares  held in the
       treasury of P-B, which will be canceled) will be converted into the right
       to receive 0.88 of a fully paid and nonassessable share of Nellcor Common
       Stock. Cash will be delivered in lieu of fractional shares. The Merger is
       more   completely   described   in    the   accompanying   Joint    Proxy
       Statement/Prospectus,  and a copy of the  Merger Agreement is attached as
       Annex A thereto.

    2.  To  consider approval  of an amendment  to the  Restated Certificate  of
       Incorporation  of Nellcor to  change Nellcor's corporate  name to Nellcor
       Puritan Bennett Incorporated.

    3.  To  consider approval  of the adoption  of Nellcor's  1995 Merger  Stock
       Incentive Plan (the "1995 Plan").

    4.   To consider approval of the  adoption of an amendment to Nellcor's 1994
       Equity Incentive Plan to increase the number of shares of Nellcor  Common
       Stock  authorized  for  issuance  thereunder  from  1,500,000  shares  to
       2,500,000 shares (the "1994 Plan Amendment").

    5.  To transact such other business as may properly come before the  meeting
       or any adjournments or postponements thereof.

    The  Board of Directors has fixed the close  of business on July 14, 1995 as
the record date  for the determination  of the holders  of Nellcor Common  Stock
entitled to notice of, and to vote at, the Special Meeting. The affirmative vote
of  a majority of the total votes cast is necessary for approval of the proposed
issuance of Nellcor Common Stock in connection with the Merger. The  affirmative
vote  of the holders of  a majority of the  outstanding shares of Nellcor Common
Stock entitled to  vote thereon  is necessary for  approval of  the proposal  to
amend  Nellcor's Restated Certificate of  Incorporation. The affirmative vote of
the holders of  a majority of  the shares  of Nellcor Common  Stock present,  or
represented,  and entitled to  vote at the Nellcor  Special Meeting is necessary
for approval of the adoption of the 1995 Plan and the 1994 Plan Amendment.
<PAGE>
    ALL STOCKHOLDERS ARE  CORDIALLY INVITED  TO ATTEND THE  SPECIAL MEETING.  TO
ENSURE  YOUR REPRESENTATION  AT THE SPECIAL  MEETING, HOWEVER, YOU  ARE URGED TO
COMPLETE, DATE, SIGN AND  RETURN THE ENCLOSED PROXY  AS PROMPTLY AS POSSIBLE.  A
POSTAGE-PREPAID ENVELOPE IS ENCLOSED FOR THAT PURPOSE. ANY STOCKHOLDER ATTENDING
THE  SPECIAL MEETING MAY VOTE IN PERSON  EVEN IF THAT STOCKHOLDER HAS RETURNED A
PROXY.

                                          By Order of the Board of Directors,

                                          Laureen DeBuono
                                          EXECUTIVE VICE PRESIDENT, HUMAN
                                          RESOURCES,
                                          GENERAL COUNSEL AND SECRETARY

Dated: July 24, 1995
<PAGE>
                          [PURITAN-BENNETT LETTERHEAD]

                                                                   July 24, 1995

Dear Stockholder:

    You are cordially invited to attend  the Special Meeting of Stockholders  of
Puritan-Bennett Corporation ("P-B") to be held at 12:00 Noon on August 24, 1995,
at  the offices  of P-B,  9401 Indian Creek  Parkway, Suite  300, Overland Park,
Kansas 66210.

    At the Special  Meeting, you will  be asked  to consider and  vote upon  the
following proposal:

        To approve the adoption of the Agreement and Plan of Merger, dated as of
       May  21, 1995 and  amended as of  June 30, 1995  (as amended, the "Merger
       Agreement"), by and among  Nellcor Incorporated ("Nellcor"), Puma  Merger
       Corporation,  a  Delaware corporation  and  a wholly-owned  subsidiary of
       Nellcor ("Sub"),  and P-B,  pursuant to  which Sub  will be  merged  (the
       "Merger")  with and into  P-B. Following consummation  of the Merger, P-B
       will be  a  wholly-owned  subsidiary  of Nellcor.  In  the  Merger,  each
       outstanding  share of  P-B Common  Stock (other  than shares  held in the
       treasury of P-B, which will be canceled) will be converted into the right
       to receive 0.88 of a fully paid and nonassessable share of Nellcor Common
       Stock. Cash will be delivered in lieu of fractional shares.

    At the Special Meeting, you may also be asked to consider and vote upon such
other business as may properly come  before the meeting or any postponements  or
adjournments thereof.

    YOUR  BOARD  HAS UNANIMOUSLY  APPROVED THE  TERMS  OF THE  MERGER AGREEMENT,
BELIEVES THAT THE TERMS  OF THE MERGER  AGREEMENT ARE FAIR TO,  AND IN THE  BEST
INTERESTS  OF, P-B AND ITS STOCKHOLDERS, AND UNANIMOUSLY RECOMMENDS THAT HOLDERS
OF SHARES OF P-B COMMON STOCK VOTE "FOR" APPROVAL OF THE MERGER AGREEMENT.

    The  accompanying   Joint  Proxy   Statement/Prospectus  provides   detailed
information concerning the proposed Merger and additional information, which you
are  urged to  read carefully. It  is important  that your shares  of P-B Common
Stock be represented at the Special Meeting, regardless of the number of  shares
you  hold. Therefore, please  sign, date and  return your proxy  card as soon as
possible, whether or not you plan to  attend the Special Meeting. This will  not
prevent  you from  voting your  shares in person  if you  subsequently choose to
attend the Special Meeting.

                                          On behalf of the Board of Directors,

                                          Burton A. Dole, Jr.
                                          CHAIRMAN, PRESIDENT AND
                                          CHIEF EXECUTIVE OFFICER
<PAGE>
                          PURITAN-BENNETT CORPORATION
                           9401 INDIAN CREEK PARKWAY
                          OVERLAND PARK, KANSAS 66210

                            ------------------------

                   NOTICE OF SPECIAL MEETING OF STOCKHOLDERS
                           TO BE HELD AUGUST 24, 1995

                            ------------------------

To the Stockholders of Puritan-Bennett Corporation:

    A Special Meeting of Stockholders of Puritan-Bennett Corporation, a Delaware
corporation ("P-B"), will  be held  at 12:00  Noon on  August 24,  1995, at  the
offices  of P-B,  9401 Indian  Creek Parkway,  Suite 300,  Overland Park, Kansas
66210 for the following purposes:

    1.  To consider the adoption of  the Agreement and Plan of Merger, dated  as
       of  May 21, 1995 and amended as of June 30, 1995 (as amended, the "Merger
       Agreement"), by and among  Nellcor Incorporated ("Nellcor"), Puma  Merger
       Corporation,  a  Delaware corporation  and  a wholly-owned  subsidiary of
       Nellcor ("Sub"), and P-B, a copy of  which is attached as Annex A to  the
       Joint  Proxy Statement/ Prospectus accompanying  this Notice, pursuant to
       which Sub will be merged (the "Merger")  with and into P-B, and P-B  will
       become  a  wholly-owned  subsidiary  of  Nellcor.  In  the  Merger,  each
       outstanding share of  P-B Common  Stock (other  than shares  held in  the
       treasury of P-B, which will be canceled) will be converted into the right
       to receive 0.88 of a fully paid and nonassessable share of Nellcor Common
       Stock. Cash will be delivered in lieu of fractional shares.

    2.   To transact such other business as may properly come before the meeting
       or any adjournments or postponements thereof.

    The Board of Directors has fixed the close of business on July 14, 1995,  as
the  record  date for  the  determination of  the  holders of  P-B  Common Stock
entitled to notice  of, and to  vote at,  the Special Meeting.  Approval of  the
proposal  to  adopt the  Merger  Agreement requires  the  affirmative vote  of a
majority of the outstanding shares of P-B Common Stock entitled to vote thereon.
The  Merger  and  other  related  matters  are  more  fully  described  in   the
accompanying  Joint Proxy  Statement/Prospectus, and the  annexes thereto, which
form a part of this Notice.

    ALL STOCKHOLDERS ARE  CORDIALLY INVITED  TO ATTEND THE  SPECIAL MEETING.  TO
ENSURE  YOUR REPRESENTATION  AT THE SPECIAL  MEETING, HOWEVER, YOU  ARE URGED TO
COMPLETE, DATE, SIGN AND  RETURN THE ENCLOSED PROXY  AS PROMPTLY AS POSSIBLE.  A
POSTAGE-PREPAID ENVELOPE IS ENCLOSED FOR THAT PURPOSE. ANY STOCKHOLDER ATTENDING
THE  SPECIAL MEETING MAY VOTE IN PERSON  EVEN IF THAT STOCKHOLDER HAS RETURNED A
PROXY.

                                          By Order of the Board of Directors,

                                          Daniel C. Weary
                                          GENERAL COUNSEL AND SECRETARY

Dated: July 24, 1995

      PLEASE DO NOT SEND IN ANY CERTIFICATES FOR YOUR SHARES AT THIS TIME.
<PAGE>
                              NELLCOR INCORPORATED
                                      AND
                          PURITAN-BENNETT CORPORATION
                             JOINT PROXY STATEMENT

                              NELLCOR INCORPORATED

                                   PROSPECTUS

    This  Joint  Proxy  Statement/Prospectus  ("Proxy  Statement/Prospectus") is
being furnished to the holders of common  stock, $.001 par value per share  (the
"Nellcor  Common  Stock"),  of  Nellcor  Incorporated,  a  Delaware  corporation
("Nellcor"), in connection  with the  solicitation of  proxies by  the Board  of
Directors  of Nellcor for use at a Special Meeting of Stockholders of Nellcor to
be held  at Nellcor's  offices at  4280 Hacienda  Drive, Pleasanton,  California
94588  on August  24, 1995  at 10:00 A.M.,  and at  any and  all adjournments or
postponements thereof (the "Nellcor Special Meeting").

    This Proxy Statement/Prospectus also  is being furnished  to the holders  of
common   stock,  $1.00  par  value  per  share  (the  "P-B  Common  Stock"),  of
Puritan-Bennett Corporation, a Delaware corporation ("P-B"), in connection  with
the  solicitation of  proxies by  the Board  of Directors  of P-B  for use  at a
Special Meeting of  Stockholders of  P-B to  be held  at P-B's  offices at  9401
Indian  Creek Parkway,  Suite 300,  Overland Park,  Kansas 66210,  on August 24,
1995, at 12:00 Noon,  and at any and  all adjournments or postponements  thereof
(the "P-B Special Meeting").

    This Proxy Statement/Prospectus relates to the Agreement and Plan of Merger,
dated  as of  May 21,  1995 and  amended as  of June  30, 1995  (as amended, the
"Merger Agreement"), by and among  Nellcor, Puma Merger Corporation, a  Delaware
corporation  and a wholly-owned subsidiary of Nellcor ("Sub"), and P-B, pursuant
to which Sub will be  merged (the "Merger") with and  into P-B, and P-B will  be
the  surviving  corporation  (the  "Surviving  Corporation")  as  a wholly-owned
subsidiary of Nellcor. In the Merger, each outstanding share of P-B Common Stock
(other than  shares  held in  the  treasury of  P-B,  which will  be  canceled),
together  with the  associated P-B Common  Stock Purchase  Right (as hereinafter
defined), will be converted into the right  to receive 0.88 of a fully paid  and
nonassessable  share  of  Nellcor  Common  Stock,  including  the  corresponding
percentage of a Nellcor Preferred Stock Purchase Right (as hereinafter defined).
Cash will be delivered in lieu of fractional shares. Consummation of the  Merger
is  subject to various conditions, including adoption at the P-B Special Meeting
of the Merger Agreement by the holders  of a majority of the outstanding  shares
of  P-B  Common Stock  entitled to  vote  thereon and  approval of  the proposed
issuance of shares of Nellcor  Common Stock in connection  with the Merger by  a
majority  of  the total  votes  cast on  such  proposal at  the  Nellcor Special
Meeting. At the Nellcor Special Meeting, Nellcor stockholders will also be asked
to approve a proposed amendment to the Restated Certificate of Incorporation  of
Nellcor   to  change  Nellcor's  corporate   name  to  Nellcor  Puritan  Bennett
Incorporated, and  to  approve  the  adoption of  Nellcor's  1995  Merger  Stock
Incentive Plan and an amendment to Nellcor's 1994 Equity Incentive Plan.

   
    This Proxy Statement/Prospectus also constitutes a prospectus of Nellcor for
the  issuance of up to 11,860,150 shares  of Nellcor Common Stock and associated
Nellcor Preferred Stock  Purchase Rights  to be  issued in  connection with  the
Merger.  Nellcor Common Stock is listed and traded on the Nasdaq National Market
("Nasdaq") under the symbol  "NELL." On July 20,  1995, the closing sales  price
for Nellcor Common Stock as reported on Nasdaq was $47.625 per share.
    

    All information contained in this Proxy Statement/Prospectus with respect to
Nellcor  and Sub has been provided by Nellcor. All information contained in this
Proxy Statement/Prospectus with respect  to P-B has been  provided by P-B.  This
Proxy  Statement/Prospectus and the accompanying forms  of proxy are first being
mailed to  stockholders  of  Nellcor and  P-B  on  or about  July  24,  1995.  A
stockholder  who  has given  a proxy  may revoke  it  at any  time prior  to its
exercise. See  "The  Nellcor Special  Meeting  -- Record  Date;  Voting  Rights;
Proxies" and "The P-B Special Meeting -- Record Date; Voting Rights; Proxies."

    SEE  "INVESTMENT  CONSIDERATIONS"  FOR CERTAIN  INFORMATION  THAT  SHOULD BE
CONSIDERED BY BOTH NELLCOR AND P-B STOCKHOLDERS.

THESE SECURITIES HAVE NOT  BEEN APPROVED OR DISAPPROVED  BY THE SECURITIES  AND
 EXCHANGE   COMMISSION  OR  ANY  STATE  SECURITIES  COMMISSION  NOR  HAS  THE
   SECURITIES AND  EXCHANGE COMMISSION  OR ANY  STATE SECURITIES  COMMISSION
    PASSED    UPON    THE   ACCURACY    OR    ADEQUACY   OF    THIS   PROXY
     STATEMENT/PROSPECTUS. ANY       REPRESENTATION TO THE  CONTRARY IS  A
                               CRIMINAL OFFENSE.
                           --------------------------

          THE DATE OF THIS PROXY STATEMENT/PROSPECTUS IS JULY 24, 1995
<PAGE>
                             AVAILABLE INFORMATION

    Nellcor   has  filed  with  the  Securities  and  Exchange  Commission  (the
"Commission"), a Registration Statement on  Form S-4 (including all  amendments,
exhibits, annexes and schedules thereto, the "Registration Statement"), pursuant
to  the Securities Act of 1933, as amended (the "Securities Act"), and the rules
and regulations promulgated  thereunder, covering the  Nellcor Common Stock  and
the  associated Nellcor  Preferred Stock  Purchase Rights  being offered hereby.
This Proxy Statement/  Prospectus does not  contain all of  the information  set
forth  in  the Registration  Statement, certain  parts of  which are  omitted in
accordance with  the  rules  and  regulations of  the  Commission.  For  further
information,  reference is hereby made to the Registration Statement. Statements
made in this  Proxy Statement/Prospectus  as to  the contents  of any  contract,
agreement  or other document are not  necessarily complete. With respect to each
such  contract,  agreement  or  other  document  filed  as  an  exhibit  to  the
Registration Statement or incorporated by reference herein, reference is made to
the  exhibit for a more  complete description of the  matters involved, and each
such statement shall be deemed qualified in its entirety by such reference.  The
Registration Statement, including exhibits filed as a part thereof, is available
at the Commission for inspection and copying as set forth below.

    Nellcor  and  P-B  are  subject to  the  informational  requirements  of the
Securities Exchange  Act  of 1934,  as  amended  (the "Exchange  Act"),  and  in
accordance  therewith file reports, proxy  statements and other information with
the Commission.  Such reports,  proxy statements  and other  information may  be
inspected  and  copied  at the  public  reference facilities  maintained  by the
Commission at Room 1024,  Judiciary Plaza, 450  Fifth Street, N.W.,  Washington,
D.C.  20549 and  at the  following Regional  Offices of  the Commission: Chicago
Regional Office,  Northwestern Atrium  Center, 500  West Madison  Street,  Suite
1400,  Chicago,  Illinois 60661;  and New  York Regional  Office, 7  World Trade
Center, 13th Floor, New York,  New York 10048. Copies  of such materials can  be
obtained at prescribed rates from the Public Reference Section of the Commission
at Judiciary Plaza, 450 Fifth Street, N.W., Washington, D.C. 20549. In addition,
material  filed  by Nellcor  and  P-B can  be inspected  at  the offices  of the
National Association  of Securities  Dealers, Reports  Section, 1735  K  Street,
N.W., Washington, D.C. 20006.

    THIS PROXY STATEMENT/PROSPECTUS INCORPORATES BY REFERENCE DOCUMENTS RELATING
TO  NELLCOR AND  TO P-B  THAT ARE  NOT PRESENTED  HEREIN OR  DELIVERED HEREWITH.
NELLCOR  WILL  PROVIDE  WITHOUT  CHARGE  TO  ANY  PERSON  TO  WHOM  THIS   PROXY
STATEMENT/PROSPECTUS  IS DELIVERED,  INCLUDING ANY  BENEFICIAL OWNER  OF NELLCOR
COMMON STOCK OR P-B COMMON STOCK, UPON WRITTEN OR ORAL REQUEST OF SUCH PERSON, A
COPY OF ANY OR ALL  SUCH DOCUMENTS RELATING TO  NELLCOR (OTHER THAN EXHIBITS  TO
SUCH  DOCUMENTS  THAT ARE  NOT SPECIFICALLY  INCORPORATED HEREIN  BY REFERENCE).
WRITTEN REQUESTS FOR SUCH DOCUMENTS SHOULD BE DIRECTED TO NELLCOR  INCORPORATED,
4280   HACIENDA  DRIVE,   PLEASANTON,  CALIFORNIA   94588,  ATTENTION:  INVESTOR
RELATIONS;  AND  TELEPHONE  REQUESTS  MAY  BE  DIRECTED  TO  NELLCOR'S  INVESTOR
RELATIONS  DEPARTMENT AT (510) 463-4039. P-B  WILL PROVIDE WITHOUT CHARGE TO ANY
PERSON TO  WHOM  THIS PROXY  STATEMENT/PROSPECTUS  IS DELIVERED,  INCLUDING  ANY
BENEFICIAL  OWNER OF NELLCOR COMMON  STOCK OR P-B COMMON  STOCK, UPON WRITTEN OR
ORAL REQUEST OF SUCH PERSON, A COPY OF ANY OR ALL SUCH DOCUMENTS RELATING TO P-B
(OTHER THAN EXHIBITS TO  SUCH DOCUMENTS THAT  ARE NOT SPECIFICALLY  INCORPORATED
HEREIN  BY REFERENCE). WRITTEN REQUESTS FOR SUCH DOCUMENTS SHOULD BE DIRECTED TO
PURITAN-BENNETT CORPORATION, 9401  INDIAN CREEK PARKWAY,  OVERLAND PARK,  KANSAS
66210, ATTENTION: STOCKHOLDER SERVICES DEPARTMENT; AND TELEPHONE REQUESTS MAY BE
DIRECTED TO P-B'S STOCKHOLDER SERVICES DEPARTMENT AT (913) 661-0444. IN ORDER TO
ENSURE  TIMELY DELIVERY OF THE DOCUMENTS, ANY  REQUESTS SHOULD BE MADE BY AUGUST
17, 1995. COPIES OF  DOCUMENTS SO REQUESTED  WILL BE SENT  BY FIRST CLASS  MAIL,
POSTAGE PAID, WITHIN ONE BUSINESS DAY OF THE RECEIPT OF SUCH REQUEST.

                                       i
<PAGE>
                    INCORPORATION OF DOCUMENTS BY REFERENCE

    The  following  documents previously  filed by  Nellcor with  the Commission
pursuant to the  Exchange Act  are hereby  incorporated by  reference into  this
Proxy Statement/Prospectus:

        1.   Nellcor's  Annual Report on  Form 10-K  for the year  ended July 3,
    1994;

        2.  Nellcor's  Quarterly Reports  on Form  10-Q for  the quarters  ended
    October 2, 1994, January 1, 1995 and April 2, 1995;

        3.   Nellcor's Current Reports  on Form 8-K dated  April 3, 1995 and May
    21, 1995;

        4.   The  description of  the  Nellcor  Common Stock  contained  in  the
    Registration  Statement on  Form 8-A filed  by Nellcor  with the Commission,
    File No. 0-14980, including any amendments or reports filed for the  purpose
    of updating such description; and

        5.    The description  of the  Nellcor  Preferred Stock  Purchase Rights
    contained in the Registration  Statement on Form 8-A  filed by Nellcor  with
    the  Commission, File No. 0-14980, including any amendments or reports filed
    for the purpose of updating such description.

    The following documents previously filed by P-B with the Commission pursuant
to the  Exchange  Act are  hereby  incorporated  by reference  into  this  Proxy
Statement/Prospectus:

        1.   P-B's  Annual Report on  Form 10-K  for the year  ended January 31,
    1995;

        2.  P-B's Quarterly Report on Form 10-Q for the quarter ended April  30,
    1995;

        3.  P-B's Current Report on Form 8-K dated May 23, 1995;

        4.     The  description  of  the  P-B  Common  Stock  contained  in  the
    Registration Statement on Form  8-A filed by P-B  with the Commission,  File
    No.  0-3717, including  any amendments or  reports filed for  the purpose of
    updating such description; and

        5.  The description of the P-B Common Stock Purchase Rights contained in
    the Registration Statement  on Form 8-A  filed by P-B  with the  Commission,
    File  No. 0-3717, including any amendments  or reports filed for the purpose
    of updating such description.

    In addition,  all  reports and  other  documents  filed by  Nellcor  or  P-B
pursuant  to Section 13(a), 13(c), 14 or 15(d) of the Exchange Act subsequent to
the date hereof and prior to (a)  the date of the Nellcor Special Meeting,  with
respect  to such materials filed by Nellcor, and (b) the date of the P-B Special
Meeting, with respect  to such materials  filed by  P-B, shall be  deemed to  be
incorporated by reference herein and to be a part hereof from the date of filing
of   such  reports  and  documents.  Any   statement  contained  in  a  document
incorporated or deemed to be incorporated by reference herein shall be deemed to
be modified or superseded for purposes of this Proxy Statement/Prospectus to the
extent that a  statement contained herein,  or in any  other subsequently  filed
document  that also  is incorporated or  deemed to be  incorporated by reference
herein, modifies or supersedes such statement. Any such statement so modified or
superseded shall  not  be  deemed,  except as  so  modified  or  superseded,  to
constitute a part of this Proxy Statement/Prospectus.

    NO   PERSON  IS  AUTHORIZED   TO  GIVE  ANY  INFORMATION   OR  TO  MAKE  ANY
REPRESENTATIONS  WITH  RESPECT   TO  THE   MATTERS  DESCRIBED   IN  THIS   PROXY
STATEMENT/PROSPECTUS  OTHER  THAN THOSE  CONTAINED  HEREIN OR  IN  THE DOCUMENTS
INCORPORATED BY  REFERENCE  HEREIN.  ANY  INFORMATION  OR  REPRESENTATIONS  WITH
RESPECT  TO SUCH MATTERS NOT CONTAINED HEREIN OR THEREIN MUST NOT BE RELIED UPON
AS HAVING BEEN  AUTHORIZED BY  NELLCOR OR P-B.  THIS PROXY  STATEMENT/PROSPECTUS
DOES  NOT CONSTITUTE  AN OFFER TO  SELL, OR A  SOLICITATION OF AN  OFFER TO BUY,
SECURITIES, OR THE SOLICITATION OF A PROXY,  IN ANY JURISDICTION TO OR FROM  ANY
PERSON  TO OR FROM  WHOM IT IS UNLAWFUL  TO MAKE SUCH  OFFER, SOLICITATION OF AN
OFFER OR PROXY SOLICITATION IN SUCH  JURISDICTION. NEITHER THE DELIVERY OF  THIS
PROXY  STATEMENT/PROSPECTUS  NOR  ANY  SALE  MADE  HEREUNDER  SHALL,  UNDER  ANY
CIRCUMSTANCES, CREATE  ANY IMPLICATION  THAT THERE  HAS BEEN  NO CHANGE  IN  THE
AFFAIRS  OF NELLCOR OR P-B SINCE THE DATE HEREOF OR THAT THE INFORMATION IN THIS
PROXY STATEMENT/PROSPECTUS OR IN THE DOCUMENTS INCORPORATED BY REFERENCE  HEREIN
IS CORRECT AS OF ANY TIME SUBSEQUENT TO THE DATES HEREOF OR THEREOF.

                            ------------------------

                                       ii
<PAGE>
                               TABLE OF CONTENTS

   
<TABLE>
<CAPTION>
                                                                                                                PAGE
                                                                                                                -----
<S>                                                                                                          <C>
AVAILABLE INFORMATION......................................................................................           i
INCORPORATION OF DOCUMENTS BY REFERENCE....................................................................          ii
SUMMARY....................................................................................................           1
INVESTMENT CONSIDERATIONS..................................................................................          10
  Integration of the Businesses............................................................................          10
  Health Care Reform/Pricing Pressure......................................................................          10
  Dependence on Third Parties; Managed Care Organizations..................................................          10
  Government Regulation....................................................................................          11
  Dependence of Earnings on Certain Products...............................................................          13
  Intellectual Property Rights.............................................................................          13
  Competition..............................................................................................          14
  New Product Introductions................................................................................          14
  Product Liability Exposure...............................................................................          14
  Dependence on Key Personnel..............................................................................          15
  Employees................................................................................................          15
  Impact of Currency Fluctuations; Importance of Foreign Sales.............................................          15
  Possible Volatility of Stock Price.......................................................................          15
  Certain Anti-Takeover Provisions.........................................................................          15
  Dividend Policy..........................................................................................          16
THE NELLCOR SPECIAL MEETING................................................................................          16
  Purpose of the Nellcor Special Meeting...................................................................          16
  Record Date; Voting Rights; Proxies......................................................................          16
  Solicitation of Proxies..................................................................................          17
  Quorum...................................................................................................          17
  Required Vote............................................................................................          17
THE P-B SPECIAL MEETING....................................................................................          18
  Purpose of the P-B Special Meeting.......................................................................          18
  Record Date; Voting Rights; Proxies......................................................................          18
  Solicitation of Proxies..................................................................................          19
  Quorum...................................................................................................          19
  Required Vote............................................................................................          19
THE MERGER.................................................................................................          20
  General..................................................................................................          20
  Effective Time...........................................................................................          20
  Conversion of Shares; Procedures for Exchange of Certificates............................................          20
  Background of the Merger.................................................................................          21
  Recommendation of the Nellcor Board; Reasons for the Merger and Other Proposals..........................          24
  Recommendation of the P-B Board; Reasons for the Merger..................................................          24
  Opinions of Robertson Stephens and Goldman Sachs.........................................................          25
  Opinion of Smith Barney..................................................................................          34
  Interests of Certain Persons in the Merger...............................................................          42
  Certain Federal Income Tax Consequences..................................................................          45
  Accounting Treatment.....................................................................................          46
  Regulatory Approvals.....................................................................................          47
  Resale Restrictions......................................................................................          47
  No Appraisal Rights......................................................................................          48
THE MERGER AGREEMENT.......................................................................................          49
  The Merger...............................................................................................          49
  Effective Time of the Merger.............................................................................          49
  Conversion of Securities.................................................................................          49
</TABLE>
    

                                      iii
<PAGE>
   
<TABLE>
<S>                                                                                                          <C>
  Stock Options............................................................................................          49
  Exchange of Shares.......................................................................................          50
  Representations and Warranties...........................................................................          51
  Certain Covenants........................................................................................          51
  Compensation Plans.......................................................................................          53
  No Solicitation..........................................................................................          54
  Certain Employee Benefit Plan Matters....................................................................          54
  Director and Officer Indemnification.....................................................................          55
  P-B Accruals and Reserves................................................................................          55
  Name Change..............................................................................................          55
  Management After the Merger..............................................................................          55
  Conditions...............................................................................................          56
  Termination..............................................................................................          57
  Cancellation Fees; Expenses..............................................................................          57
  Amendment; Waiver........................................................................................          58
  Expenses.................................................................................................          58
MANAGEMENT OF NELLCOR AFTER THE MERGER.....................................................................          59
  Directors and Executive Officers After the Merger........................................................          59
  Security Ownership of Management.........................................................................          61
  Post-Merger Dividend Policy..............................................................................          61
COMPARATIVE PER SHARE PRICES AND DIVIDEND POLICIES.........................................................          61
UNAUDITED PRO FORMA COMBINED CONDENSED FINANCIAL STATEMENTS................................................          63
THE NELLCOR 1995 MERGER STOCK INCENTIVE PLAN...............................................................          68
  The 1995 Plan............................................................................................          68
  Terms of Replacement Options.............................................................................          69
  Acceleration and/or Termination in Certain Circumstances.................................................          70
  Federal Income Tax Consequences Relating to the 1995 Plan................................................          71
  New Plan Benefits........................................................................................          72
THE AMENDMENT TO NELLCOR'S 1994 EQUITY INCENTIVE PLAN......................................................          73
  Purpose..................................................................................................          73
  Administration...........................................................................................          73
  Duration, Amendment and Termination......................................................................          73
  Eligibility..............................................................................................          74
  Terms of Stock Options...................................................................................          74
  Terms of Stock Grants, Restricted Stock Grants and Restricted Stock Purchases............................          74
  Adjustment Provisions....................................................................................          75
  Federal Income Tax Consequences Relating to Stock Awards.................................................          75
  New Plan Benefits........................................................................................          76
COMPENSATION OF DIRECTORS AND CERTAIN EXECUTIVE OFFICERS OF NELLCOR........................................          77
  General..................................................................................................          77
  Other Compensation.......................................................................................          78
  Employee Stock Option Plans..............................................................................          78
  Stock Option Exercises and Holdings......................................................................          80
  Voluntary Investment Plus Plan...........................................................................          80
  Deferred Compensation Plan...............................................................................          81
  Certain Transactions.....................................................................................          81
  Indebtedness of Management...............................................................................          82
  Compensation of Directors................................................................................          82
  Nominating and Compensation Committee Interlocks and Insider Participation...............................          83
BENEFICIAL OWNERS OF NELLCOR COMMON STOCK..................................................................          84
DESCRIPTION OF CAPITAL STOCK OF NELLCOR....................................................................          85
  Authorized Capital Stock.................................................................................          85
</TABLE>
    

                                       iv
<PAGE>
   
<TABLE>
<S>                                                                                                          <C>
  Nellcor Common Stock.....................................................................................          85
  Nellcor Preferred Stock..................................................................................          85
  Preferred Stock Purchase Rights..........................................................................          86
COMPARISON OF STOCKHOLDER RIGHTS...........................................................................          87
  General..................................................................................................          87
  Classified Board of Directors............................................................................          88
  Stockholders Rights Plan.................................................................................          88
  Election and Number of Directors; Filling Vacancies; Removal.............................................          89
  Stockholders Meetings....................................................................................          89
  Stockholders Vote for Business Combinations..............................................................          90
  Common Stock.............................................................................................          92
  Preferred Stock..........................................................................................          92
  Business Combinations....................................................................................          92
  Limitation of Liability of Directors.....................................................................          93
  Indemnification of Directors and Officers................................................................          93
  Other Provisions.........................................................................................          94
  Amendment of the Certificate of Incorporation and By-Laws................................................          95
PROPOSED AMENDMENT TO NELLCOR'S RESTATED CERTIFICATE OF INCORPORATION......................................          96
OTHER MATTERS..............................................................................................          96
LEGAL MATTERS..............................................................................................          96
EXPERTS....................................................................................................          96
STOCKHOLDER PROPOSALS......................................................................................          96
</TABLE>
    

                                       v
<PAGE>
                                    ANNEXES

<TABLE>
<S>          <C>
ANNEX A      MERGER AGREEMENT

ANNEX B      AMENDMENT NO. 1 TO MERGER AGREEMENT

ANNEX C      OPINION OF ROBERTSON, STEPHENS & COMPANY, L.P.

ANNEX D      OPINION OF GOLDMAN, SACHS & CO.

ANNEX E      OPINION OF SMITH BARNEY INC.

ANNEX F      FORM OF AMENDMENT TO NELLCOR'S RESTATED CERTIFICATE OF INCORPORATION
</TABLE>

                                       vi
<PAGE>
                                    SUMMARY

    THE  FOLLOWING IS  A SUMMARY OF  CERTAIN INFORMATION  CONTAINED ELSEWHERE IN
THIS PROXY STATEMENT/ PROSPECTUS, THE ANNEXES HERETO AND DOCUMENTS  INCORPORATED
BY  REFERENCE HEREIN. THIS SUMMARY DOES NOT  CONTAIN A COMPLETE STATEMENT OF ALL
MATERIAL INFORMATION RELATING TO THE MERGER AGREEMENT, THE MERGER AND THE  OTHER
MATTERS DISCUSSED HEREIN AND IS SUBJECT TO, AND IS QUALIFIED IN ITS ENTIRETY BY,
THE MORE DETAILED INFORMATION AND FINANCIAL STATEMENTS CONTAINED OR INCORPORATED
BY REFERENCE IN THIS PROXY STATEMENT/PROSPECTUS. STOCKHOLDERS OF NELLCOR AND P-B
SHOULD  READ CAREFULLY THIS PROXY  STATEMENT/PROSPECTUS IN ITS ENTIRETY. CERTAIN
CAPITALIZED TERMS  USED IN  THIS SUMMARY  ARE DEFINED  ELSEWHERE IN  THIS  PROXY
STATEMENT/PROSPECTUS.

THE COMPANIES

    NELLCOR.   Nellcor, a corporation  organized under the laws  of the State of
Delaware, together  with its  subsidiaries,  designs, manufactures  and  markets
monitoring, diagnostic and therapeutic instruments, sensors, airway adapters and
detectors  for  the  safety  and  management  of  respiratory-impaired  patients
wherever they are  treated. Nellcor's  arterial blood  oxygen, respiratory  gas,
blood  pressure  and  apnea  instruments  provide  intermittent  and continuous,
real-time,  noninvasive   monitoring  of   physiologically  unstable   patients.
Nellcor's  wide  variety  of  oximetry  sensors  are  used  with  Nellcor's  own
instruments, instruments that  incorporate the Nellcor  oximetry OEM module  and
instruments  produced by manufacturers licensed  to use Nellcor sensors. Nellcor
also manufactures and distributes automated systems for the collection, use  and
management  of  patient  information.  Nellcor's  products  are  sold  worldwide
principally through  a  direct  sales  force,  assisted  by  clinical  education
consultants   and  specialists.   Nellcor's  products  are   also  sold  through
distributors.

    As used herein, the  term "Nellcor" refers to  Nellcor Incorporated and  its
subsidiaries,  unless the  context otherwise  requires. The  principal executive
offices of Nellcor are  located at 4280  Hacienda Drive, Pleasanton,  California
94588 and the telephone number at that address is (510) 463-4000.

    P-B.   P-B, a corporation organized under the laws of the State of Delaware,
is the successor to a business founded in 1913 that was a pioneer in the use  of
oxygen as a medicinal agent.

    P-B  is  primarily  engaged  in the  development,  manufacture  and  sale of
products related to  respiration. Such products  are used in  a wide variety  of
health  care settings (including hospitals, home care, sub-acute care, emergency
care, skilled nursing facilities and physicians offices) and on aircraft. P-B is
organized into two main business  lines, Puritan and Bennett. Bennett  primarily
covers the hospital market and includes P-B's worldwide critical care ventilator
business,  as  well as  the  CliniVision-Registered Trademark-  Respiratory Care
Management Information  System  in  the United  States,  the  holter  monitoring
product  line  worldwide  and the  portable  ventilator product  lines  that are
manufactured and sold outside the United States. Puritan includes nearly all  of
P-B's  home respiratory  care product  lines and  certain complementary products
such as  medical gas  and gas-related  equipment and  spirometry. Aero  Systems,
which  principally develops and manufactures emergency oxygen systems for use on
aircraft,  is  included  in   Puritan  because  it   shares  one  of   Puritan's
manufacturing facilities. P-B markets and sells its products worldwide through a
direct sales force and distributors.

    As used herein, the term "P-B" refers to Puritan-Bennett Corporation and its
subsidiaries,  unless the  context otherwise  requires. The  principal executive
offices of P-B are located at  9401 Indian Creek Parkway, Overland Park,  Kansas
66210 and the telephone number at that address is (913) 661-0444.

THE SPECIAL MEETINGS

    TIME, PLACE AND DATE

    A  Special  Meeting of  Stockholders of  Nellcor will  be held  at Nellcor's
offices, 4280 Hacienda Drive, Pleasanton, California 94588, on August 24,  1995,
at 10:00 A.M., Pacific Time (including any and all adjournments or postponements
thereof, the "Nellcor Special Meeting").

                                       1
<PAGE>
    A Special Meeting of Stockholders of P-B will be held at P-B's offices, 9401
Indian  Creek Parkway,  Suite 300,  Overland Park,  Kansas 66210,  on August 24,
1995, at  12:00  Noon, Central  Time  (including  any and  all  adjournments  or
postponements thereof, the "P-B Special Meeting").

    PURPOSE OF THE SPECIAL MEETINGS

    At  the  Nellcor  Special  Meeting, holders  of  Nellcor  Common  Stock will
consider and  vote  upon the  issuance  of shares  of  Nellcor Common  Stock  in
connection  with the Merger  and pursuant to the  Merger Agreement (the "Nellcor
Share Proposal"). In addition, holders of Nellcor Common Stock will consider and
vote upon a proposal to amend Nellcor's Restated Certificate of Incorporation to
change Nellcor's corporate  name to  Nellcor Puritan  Bennett Incorporated  (the
"Nellcor Charter Amendment Proposal"). Holders of Nellcor Common Stock also will
consider  and vote upon proposals  to (a) adopt the  1995 Merger Stock Incentive
Plan (the  "1995 Plan  Proposal"), which  Nellcor is  adopting pursuant  to  its
obligation  under the Merger Agreement to  issue replacement options to purchase
shares of Nellcor Common  Stock in exchange for  certain outstanding options  to
purchase  shares of P-B Common Stock, and (b) adopt an amendment to increase the
number of shares of Nellcor Common Stock authorized for issuance under Nellcor's
1994 Equity Incentive Plan from 1,500,000 to 2,500,000 (the "1994 Plan Amendment
Proposal"). If  the Nellcor  Share Proposal  is not  approved or  the Merger  is
otherwise  not  consummated,  Nellcor  will not  implement  the  Nellcor Charter
Amendment Proposal, the 1995 Plan Proposal or the 1994 Plan Amendment  Proposal.
However,  Nellcor  is  obligated under  the  terms  of the  Merger  Agreement to
implement the 1995  Plan Proposal if  the Merger is  consummated, regardless  of
whether  stockholder approval  of the 1995  Plan Proposal is  obtained. For more
detailed descriptions  of  the  Nellcor  Share  Proposal,  the  Nellcor  Charter
Amendment Proposal, the 1995 Plan Proposal and the 1994 Plan Amendment Proposal,
see  "The  Merger," "The  Merger  Agreement," "Proposed  Amendment  to Nellcor's
Restated Certificate of Incorporation," "The Nellcor 1995 Merger Stock Incentive
Plan," and "The Amendment to Nellcor's 1994 Equity Incentive Plan." Stockholders
of Nellcor will also consider and vote  upon any other matter that may  properly
come before the meeting.

    At  the P-B Special Meeting,  holders of P-B Common  Stock will consider and
vote upon a proposal to adopt the  Merger Agreement. As a result of the  Merger,
P-B  will  become a  wholly-owned  subsidiary of  Nellcor.  In the  Merger, each
outstanding share of P-B Common Stock (other than shares held in the treasury of
P-B, which will  be canceled),  together with  the associated  P-B Common  Stock
Purchase  Right (as  hereinafter defined), will  be converted into  the right to
receive 0.88 of a  fully paid and nonassessable  share of Nellcor Common  Stock,
including  the corresponding  percentage of  a Nellcor  Preferred Stock Purchase
Right (as hereinafter  defined). Cash will  be delivered in  lieu of  fractional
shares.  Stockholders of P-B will  also consider and vote  upon any other matter
that may properly come before the meeting.

    VOTES REQUIRED; RECORD DATE

    Consummation of the Merger requires  approval of the Nellcor Share  Proposal
by  the affirmative vote  of a majority of  the total votes  cast thereon at the
Nellcor Special  Meeting. Approval  of the  Nellcor Charter  Amendment  Proposal
requires  the affirmative vote of  the holders of a  majority of the outstanding
shares of Nellcor Common Stock entitled  to vote thereon at the Nellcor  Special
Meeting. Approval of the 1995 Plan Proposal and the 1994 Plan Amendment Proposal
requires  the affirmative  vote of the  holders of  a majority of  the shares of
Nellcor Common Stock present,  or represented, and entitled  to vote thereon  at
the Nellcor Special Meeting. Holders of Nellcor Common Stock are entitled to one
vote per share. Only holders of Nellcor Common stock at the close of business on
July  14, 1995 (the "Nellcor Record Date") are entitled to notice of and to vote
at the Nellcor Special  Meeting. See "The Nellcor  Special Meeting." As of  June
30,  1995, directors and executive officers of Nellcor and their affiliates were
beneficial owners of  an aggregate  of 191,934  shares of  Nellcor Common  Stock
(exclusive  of any shares issuable upon  the exercise of stock options remaining
unexercised as of such date), or approximately 1.15% of the 16,706,250 shares of
Nellcor Common  Stock that  were issued  and outstanding  as of  such date.  See
"Management  of Nellcor After  the Merger --  Security Ownership of Management."
Each of  the  directors and  executive  officers  of Nellcor  has  indicated  an
intention to

                                       2
<PAGE>
vote  all shares  of Nellcor Common  Stock beneficially  owned by him  or her in
favor of approval of the Nellcor  Share Proposal, the Nellcor Charter  Amendment
Proposal, the 1995 Plan Proposal and the 1994 Plan Amendment Proposal.

    Consummation  of the Merger also requires  approval of the proposal to adopt
the Merger Agreement by the holders of  a majority of the outstanding shares  of
P-B Common Stock entitled to vote thereon at the P-B Special Meeting. Holders of
P-B  Common Stock are entitled to one vote per share. Only holders of P-B Common
Stock at the  close of business  on July 14,  1995 (the "P-B  Record Date")  are
entitled  to notice  of and  to vote at  the P-B  Special Meeting.  See "The P-B
Special Meeting." As of June 30,  1995, directors and executive officers of  P-B
and their affiliates were beneficial owners of an aggregate of 179,276 shares of
P-B  Common Stock (exclusive of  any shares issuable upon  the exercise of stock
options remaining unexercised as  of such date), or  approximately 1.39% of  the
12,922,092  shares of P-B  Common Stock that  were issued and  outstanding as of
such date. Each of the directors and executive officers of P-B has indicated  an
intention  to vote all shares  of P-B Common Stock  beneficially owned by him or
her in favor of adoption of the Merger Agreement.

SURRENDER OF STOCK CERTIFICATES

    Nellcor has authorized The First National Bank of Boston to act as  Exchange
Agent  under the Merger Agreement (the  "Exchange Agent"). As soon as reasonably
practicable after the Effective Time (as hereinafter defined) of the Merger, the
Exchange Agent  will send  a transmittal  letter to  each P-B  stockholder.  The
transmittal  letter will contain  instructions with respect  to the surrender of
certificates representing P-B Common  Stock to be  exchanged for Nellcor  Common
Stock.  See  "The Merger  -- Conversion  of Shares;  Procedures for  Exchange of
Certificates."

    P-B STOCKHOLDERS SHOULD NOT FORWARD CERTIFICATES FOR P-B COMMON STOCK TO THE
EXCHANGE AGENT UNTIL  THEY HAVE RECEIVED  TRANSMITTAL LETTERS. P-B  STOCKHOLDERS
SHOULD NOT RETURN STOCK CERTIFICATES WITH THE ENCLOSED PROXY.

RECOMMENDATIONS OF THE BOARDS OF DIRECTORS

    THE BOARDS OF DIRECTORS OF NELLCOR AND P-B EACH HAS UNANIMOUSLY APPROVED THE
TERMS  OF THE MERGER AGREEMENT. THE BOARD  OF DIRECTORS OF NELLCOR (THE "NELLCOR
BOARD") BELIEVES THAT THE TERMS OF THE MERGER AGREEMENT ARE FAIR TO, AND IN  THE
BEST INTERESTS OF, NELLCOR AND ITS STOCKHOLDERS, AND UNANIMOUSLY RECOMMENDS THAT
HOLDERS  OF SHARES OF  NELLCOR COMMON STOCK  VOTE "FOR" APPROVAL  OF THE NELLCOR
SHARE PROPOSAL, THE NELLCOR CHARTER  AMENDMENT PROPOSAL, THE 1995 PLAN  PROPOSAL
AND  THE 1994 PLAN AMENDMENT  PROPOSAL. THE BOARD OF  DIRECTORS OF P-B (THE "P-B
BOARD") BELIEVES THAT THE TERMS OF THE MERGER AGREEMENT ARE FAIR TO, AND IN  THE
BEST  INTERESTS OF,  P-B AND ITS  STOCKHOLDERS, AND  UNANIMOUSLY RECOMMENDS THAT
HOLDERS OF  SHARES  OF  P-B COMMON  STOCK  VOTE  "FOR" APPROVAL  OF  THE  MERGER
AGREEMENT.  SEE "THE MERGER -- BACKGROUND  OF THE MERGER," "-- RECOMMENDATION OF
THE  NELLCOR  BOARD;  REASONS   FOR  THE  MERGER   AND  OTHER  PROPOSALS,"   "--
RECOMMENDATION  OF THE P-B BOARD;  REASONS FOR THE MERGER"  AND "-- INTERESTS OF
CERTAIN PERSONS IN THE MERGER."

THE MERGER

    CONVERSION OF SECURITIES

    Upon consummation of the transactions contemplated by the Merger  Agreement,
(i)  Sub will be  merged with and into  P-B, and P-B  will become a wholly-owned
subsidiary of Nellcor and (ii) each  issued and outstanding share of P-B  Common
Stock  (other than shares of P-B Common Stock held in the treasury of P-B, which
will be canceled), together with the associated P-B Common Stock Purchase Right,
will be  converted  into  the  right  to  receive  0.88  of  a  fully  paid  and
non-assessable  share (the "Exchange  Ratio") of Nellcor  Common Stock, together
with the corresponding percentage of  a Nellcor Preferred Stock Purchase  Right.
Fractional shares of Nellcor Common Stock and associated Nellcor Preferred Stock
Purchase  Rights will not be  issued in connection with  the Merger. A holder of
P-B Common Stock  otherwise entitled  to a  fractional share  of Nellcor  Common
Stock and the

                                       3
<PAGE>
associated  fractional Nellcor Preferred Stock Purchase  Right will be paid cash
in lieu of  such fractional  share and associated  fractional Nellcor  Preferred
Stock  Purchase  Right  in an  amount  equal  to the  product  of  such fraction
multiplied by  the closing  sales price  per share  of Nellcor  Common Stock  on
Nasdaq   on  the  business  day  immediately  preceding  the  Closing  Date  (as
hereinafter defined). See "The  Merger -- Conversion  of Shares; Procedures  for
Exchange  of Securities" and "The Merger  Agreement -- Conversion of Securities"
and "-- Exchange of Shares."

    CONDITIONS TO THE MERGER; TERMINATION

    The obligations of Nellcor and P-B to  effect the Merger are subject to  the
satisfaction  of  certain  conditions, including,  among  others:  (i) obtaining
requisite regulatory approvals (including the  expiration or termination of  the
waiting  period under the Hart-Scott-Rodino  Antitrust Improvements Act of 1976,
as amended (the  "HSR Act"),  which already has  occurred) and  Nellcor and  P-B
stockholder  approvals; (ii) the effectiveness of the Registration Statement and
receipt of  all  necessary approvals  under  state securities  laws;  (iii)  the
absence  of any injunction prohibiting consummation  of the Merger; (iv) receipt
of  all  necessary  government  and  other  consents  and  approvals,  and   the
satisfaction  of any conditions  with respect thereto (other  than the filing of
the Certificate of  Merger (as  hereinafter defined));  (v) the  absence of  any
action  by any federal  or state governmental entity  that imposes any condition
upon the Surviving Corporation, Nellcor or  P-B that would so impact the  Merger
as  to render the Merger inadvisable;  (vi) receipt of accountants' letters with
respect to the qualification  of the Merger as  a "pooling of interests";  (vii)
receipt of legal opinions with respect to the tax consequences of the Merger and
other  matters; and (viii) the  absence of any change,  or any event involving a
prospective change, in the other  party's business, assets, financial  condition
or  results of operation which has had, or  is reasonably likely to have, in the
aggregate a material adverse effect on such party and its subsidiaries taken  as
a  whole (other than  as a result of  changes or proposed  changes in federal or
state health care (including health  care reimbursement) laws or regulations  of
general  applicability or interpretations thereof, changes in generally accepted
accounting  principles  and  changes   that  could,  under  the   circumstances,
reasonably  have been anticipated in light of disclosures made in writing by the
other party prior  to the execution  of the Merger  Agreement). See "The  Merger
Agreement -- Conditions."

    The  Merger Agreement is subject to termination by either Nellcor or P-B if,
among other things,  the Merger  is not consummated  by December  31, 1995.  The
Merger  Agreement also may  be terminated by  either Nellcor or  P-B under other
circumstances, including the  failure of Nellcor's  stockholders to approve  the
Nellcor Share Proposal or of P-B's stockholders to approve the proposal to adopt
the  Merger Agreement. Under certain circumstances leading to termination of the
Merger Agreement, Nellcor or P-B, as the case may be, may be entitled to receive
a cancellation fee or  expenses. See "The Merger  Agreement -- Termination"  and
"-- Cancellation Fees; Expenses."

    APPRAISAL RIGHTS

    Under the General Corporation Law of the State of Delaware (the "DGCL"), the
holders  of  Nellcor Common  Stock  are not  entitled  to appraisal  rights with
respect to the Merger, the Nellcor Share Proposal or any of the other  proposals
being  submitted to Nellcor's  stockholders and holders of  P-B Common Stock are
not entitled to appraisal rights with respect to the Merger. See "The Merger  --
No Appraisal Rights."

    GOVERNMENTAL APPROVALS REQUIRED

    Certain  aspects  of  the  Merger  will  require  notifications  to,  and/or
approvals from, certain United States authorities. Nellcor and P-B believe  that
all material notifications, filings and approvals have been made or obtained, or
will  be made  or obtained, as  the case may  be. See "The  Merger -- Regulatory
Approvals."

    ACCOUNTING TREATMENT

    The Merger is expected to be treated by Nellcor as a "pooling of  interests"
transaction for accounting and financial reporting purposes. Consummation of the
Merger is conditioned upon the

                                       4
<PAGE>
delivery   of  letters   from  Price   Waterhouse  LLP,   Nellcor's  independent
accountants, and  Ernst &  Young  LLP, P-B's  independent accountants,  to  this
effect.  See "The Merger  -- Accounting Treatment" and  "The Merger Agreement --
Conditions."

    DIRECTORS OF NELLCOR AFTER THE MERGER

    In the Merger Agreement, Nellcor has agreed to take all action necessary  to
cause Burton A. Dole, Jr. and Thomas A. McDonnell to be appointed to the Nellcor
Board,  effective as  of the Effective  Time, for  a term expiring  at the first
annual meeting of Nellcor's stockholders after the Merger. Mr. Dole is currently
Chairman, President and  Chief Executive  Officer of  P-B and  Mr. McDonnell  is
currently  a director  of P-B.  In addition,  Nellcor has  agreed in  the Merger
Agreement to nominate  Mr. Dole and  Mr. McDonnell for  reelection at the  first
annual  meeting of Nellcor's stockholders following  the Merger, and to nominate
for election as an additional director of Nellcor at such first annual meeting a
person selected by Nellcor who is not  a current or former officer, director  or
employee of P-B and who is mutually agreeable to Mr. Dole and Mr. McDonnell. See
"The  Merger  --  Interests  of  Certain Persons  in  the  Merger,"  "The Merger
Agreement -- Management After the Merger"  and "Management of Nellcor After  the
Merger."

OPINIONS OF FINANCIAL ADVISORS AND GOLDMAN SACHS

    Robertson,  Stephens  & Company,  L.P. ("Robertson  Stephens") has  acted as
financial advisor to Nellcor in connection  with the Merger and has delivered  a
written opinion, dated May 21, 1995, to the Nellcor Board to the effect that the
Exchange  Ratio was fair to Nellcor and its stockholders, from a financial point
of view, as of the date of such opinion.

    Goldman, Sachs & Co. ("Goldman  Sachs") have delivered their opinion,  dated
May  21, 1995, to the Nellcor  Board to the effect that,  as of the date of such
opinion, the  Exchange  Ratio pursuant  to  the  Merger Agreement  was  fair  to
Nellcor.

    Smith  Barney Inc. ("Smith Barney") has acted as financial advisor to P-B in
connection with the Merger  and has delivered a  written opinion, dated May  21,
1995,  to the P-B Board that  the Exchange Ratio was fair  to the holders of P-B
Common Stock, from a financial point of view, as of the date of such opinion.

    Copies of  the written  opinions of  Robertson Stephens,  Goldman Sachs  and
Smith   Barney,  which  set  forth  the  respective  assumptions  made,  matters
considered and limitations on the reviews undertaken, are attached as Annexes C,
D and E,  respectively, to this  Proxy Statement/Prospectus and  should be  read
carefully  in their entirety. See "The  Merger -- Opinions of Robertson Stephens
and Goldman Sachs" and "The Merger -- Opinion of Smith Barney."

INTERESTS OF CERTAIN PERSONS IN THE MERGER

    In considering  the recommendation  of the  P-B Board  with respect  to  the
approval  by the P-B stockholders of the  proposal to adopt the Merger Agreement
and the transactions  contemplated thereby,  stockholders should  be aware  that
certain  members of P-B management  and the P-B Board  have certain interests in
the Merger  that  are  in addition  to  the  interests of  stockholders  of  P-B
generally.  These  interests arise  from, among  other things,  certain employee
benefit  plans,  indemnification  and  insurance  arrangements  and   employment
agreements  among Nellcor, P-B  and directors and  certain executive officers of
P-B. In  addition, two  members of  the P-B  Board will  become members  of  the
Nellcor  Board after the Merger. See "The Merger -- Interests of Certain Persons
in the  Merger," "The  Merger  Agreement --  Management  After the  Merger"  and
"Management  of Nellcor  After the  Merger --  Directors and  Executive Officers
After the Merger."

INVESTMENT CONSIDERATIONS

    In considering whether to  approve the Nellcor Share  Proposal or adopt  the
Merger  Agreement, as the case may be, Nellcor stockholders and P-B stockholders
should carefully review and consider  the information contained below under  the
caption "Investment Considerations."

CERTAIN FEDERAL INCOME TAX CONSEQUENCES

    It  is anticipated  that the Merger  will constitute  a "reorganization" for
federal income  tax purposes  and, accordingly,  that no  gain or  loss will  be
recognized  by P-B stockholders (except with respect to cash received in lieu of
fractional shares), Nellcor  stockholders, Nellcor  or P-B  as a  result of  the

                                       5
<PAGE>
Merger.  Consummation of the Merger is conditioned upon the delivery of opinions
of counsel  to  this effect.  See  "The Merger  --  Certain Federal  Income  Tax
Consequences" and "The Merger Agreement -- Conditions."

COMPARATIVE RIGHTS OF STOCKHOLDERS

    The  rights of  P-B stockholders are  currently governed by  the DGCL, P-B's
Restated  Certificate  of  Incorporation,  P-B's  By-Laws  and  the  P-B  Rights
Agreement  (as  hereinafter  defined).  Upon  consummation  of  the  Merger, P-B
stockholders will  become stockholders  of  Nellcor, which  is also  a  Delaware
corporation,  and their rights  as Nellcor stockholders will  be governed by the
DGCL, Nellcor's Restated Certificate of Incorporation, Nellcor's By-Laws and the
Nellcor Rights  Agreement (as  hereinafter  defined). For  a discussion  of  the
various  differences between the rights of  stockholders of P-B and Nellcor, see
"Comparison of Stockholder Rights."

COMPARATIVE PER SHARE PRICES AND DIVIDEND POLICIES

    Both the Nellcor Common Stock and the P-B Common Stock are listed and traded
on Nasdaq. The following table sets forth the high and low sale prices per share
of Nellcor  Common  Stock  and  P-B  Common  Stock  for  the  calendar  quarters
indicated, as reported by Nasdaq.

   
<TABLE>
<CAPTION>
                                                                  NELLCOR                 P-B
                                                                COMMON STOCK          COMMON STOCK
                                                            --------------------  --------------------
                                                              HIGH        LOW       HIGH        LOW
                                                            ---------  ---------  ---------  ---------
<S>                                                         <C>        <C>        <C>        <C>
Calendar 1993:
  First Quarter...........................................  $   34.25  $  20.00   $  34.00   $  20.75
  Second Quarter..........................................      25.25     17.50      23.00      13.25
  Third Quarter...........................................      23.50     19.00      22.75      16.25
  Fourth Quarter..........................................      26.50     19.75      17.50      14.50
Calendar 1994:
  First Quarter...........................................      29.50     24.25      21.75      15.00
  Second Quarter..........................................      28.75     24.375     22.75      16.75
  Third Quarter...........................................      31.50     26.00      20.00      15.25
  Fourth Quarter..........................................      34.00     28.25      26.25      15.75
Calendar 1995:
  First Quarter...........................................      38.25     31.50      24.50      20.25
  Second Quarter..........................................      47.75     36.00      40.50      21.75
  Third Quarter (through July 20).........................      50.75     44.00      43.625     38.375
</TABLE>
    

   
    On  May 19, 1995, the  last trading day prior  to announcement of the Merger
Agreement, the closing sales prices of Nellcor Common Stock and P-B Common Stock
as reported by Nasdaq were $41.25 per share and $26.125 per share, respectively.
Based on the  Exchange Ratio  of 0.88,  the equivalent  per share  value of  P-B
Common  Stock as of  such date was $36.30.  On July 20,  1995, the closing sales
prices of Nellcor Common Stock and P-B  Common Stock as reported by Nasdaq  were
$47.625  per share  and $41.125 per  share, respectively. Based  on the Exchange
Ratio of 0.88, the  equivalent per share  value of P-B Common  Stock as of  such
date was $41.91.
    

    Because  the Exchange Ratio is fixed at 0.88 and because the market price of
Nellcor Common Stock is subject to  fluctuation, the market value of the  shares
of  Nellcor Common Stock  that holders of  P-B Common Stock  will receive in the
Merger may increase or decrease prior to and following the Merger.  STOCKHOLDERS
ARE  URGED TO OBTAIN CURRENT MARKET QUOTATIONS  FOR NELLCOR COMMON STOCK AND P-B
COMMON STOCK. NO ASSURANCE CAN BE GIVEN  AS TO THE FUTURE PRICES OR MARKETS  FOR
NELLCOR COMMON STOCK OR P-B COMMON STOCK.

    In  August 1976, P-B initiated payment  of a regular quarterly dividend. The
current dividend  of $0.03  per share  was established  in March  1990.  Pending
consummation  of the Merger, P-B has agreed  to cease paying dividends after its
May 1995 regular cash dividend. See "The Merger Agreement -- Certain Covenants."
No dividends have been declared or paid on Nellcor Common Stock since  Nellcor's
incorporation,  nor  are  any  such  dividends  expected  to  be  paid following
consummation of the Merger.

                                       6
<PAGE>
SELECTED HISTORICAL FINANCIAL DATA
    The following selected  historical financial  data of Nellcor  and P-B  have
been derived from their respective historical financial statements and should be
read  in conjunction with  such consolidated financial  statements and the notes
thereto included  or  incorporated by  reference  herein. The  Nellcor  and  P-B
historical  financial data as of and for the nine months ended April 2, 1995 and
April 3, 1994 and as of and for the three months ended April 30, 1995 and  1994,
respectively,  have been derived from  unaudited financial statements of Nellcor
or P-B, as the  case may be,  and have been  prepared on the  same basis as  the
historical information derived from audited financial statements. In the opinion
of  the managements  of Nellcor and  P-B, respectively,  the unaudited financial
statements of Nellcor or P-B, as the case may be, from which such data have been
derived contain all adjustments, consisting  only of normal recurring  accruals,
necessary  for the fair presentation  of the results for, and  as of the end of,
such periods. No  cash dividends have  been declared or  paid on Nellcor  Common
Stock. The operating results of Nellcor for the nine months ended April 2, 1995,
and  the operating results of P-B for the three months ended April 30, 1995, are
not necessarily indicative  of the results  that may be  expected for the  years
ending  July 2, 1995, in the case of  Nellcor, and January 31, 1996, in the case
of P-B.

                       SELECTED HISTORICAL FINANCIAL DATA
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
NELLCOR

<TABLE>
<CAPTION>
                                                                                                    NINE MONTHS ENDED
                                                              FISCAL YEAR ENDED
                                            -----------------------------------------------------  --------------------
                                             JULY 3,    JULY 4,    JULY 5,    JULY 7,    JULY 1,   APRIL 2,   APRIL 3,
                                              1994       1993       1992       1991       1990       1995       1994
                                            ---------  ---------  ---------  ---------  ---------  ---------  ---------
<S>                                         <C>        <C>        <C>        <C>        <C>        <C>        <C>
HISTORICAL STATEMENT OF OPERATIONS DATA:
  Net revenue.............................  $ 234,972  $ 218,186  $ 196,164  $ 158,929  $ 142,557  $ 190,766  $ 169,907
  Income from operations..................     42,851     37,837     30,988     22,360     19,740     36,737     29,554
  Net income from operations..............     20,557     25,120     21,293     16,262     14,435     25,400     21,067
  Net income from operations per share....       1.22       1.50       1.31       1.05       0.96       1.51       1.25
  Common dividends per share..............     --         --         --         --         --         --         --
  Shares used to compute net income from
   operations per share...................     16,843     16,745     16,281     15,457     15,024     16,857     16,857
HISTORICAL BALANCE SHEET DATA:
  Working capital.........................  $ 154,827  $ 143,686  $ 108,527  $  96,201  $  72,777  $ 175,448  $ 164,935
  Total assets............................    238,148    225,606    188,654    142,836    121,286    263,558    249,841
  Long-term obligations...................     --         --         --         --            674     --          1,886
  Stockholders' equity....................    204,113    192,464    154,492    121,384     97,815    224,840    213,593
</TABLE>

P-B

<TABLE>
<CAPTION>
                                                             FISCAL YEAR ENDED
                                           -----------------------------------------------------
                                                                                                   THREE MONTHS ENDED
                                                     JANUARY 31,              DECEMBER 31,(1)          APRIL 30,
                                           -------------------------------  --------------------  --------------------
                                             1995      1994(2)     1993       1991       1990       1995       1994
                                           ---------  ---------  ---------  ---------  ---------  ---------  ---------
<S>                                        <C>        <C>        <C>        <C>        <C>        <C>        <C>
HISTORICAL STATEMENT OF OPERATIONS DATA:
  Net revenue............................  $ 336,026  $ 309,255  $ 300,060  $ 256,122  $ 251,876  $  84,493  $  80,408
  Income/(loss) from operations..........     20,895    (35,141)    21,125        440     23,549      8,892      5,058
  Net income/(loss) from operations......      8,398    (31,779)    14,595        574     15,873      6,377      3,724
  Net income/(loss) from operations per
   share.................................       0.67      (2.66)      1.24       0.05       1.39       0.51       0.30
  Common dividends per share.............       0.12       0.12       0.12       0.12       0.12       0.03       0.03
  Shares used to compute net
   income/(loss) from operations per
   share.................................     12,509     11,956     11,812     11,617     11,451     12,618     12,432

HISTORICAL BALANCE SHEET DATA:
  Working capital........................  $  73,572  $  51,882  $  81,086  $  70,847  $  81,405  $  82,154  $  54,390
  Total assets...........................    273,135    256,594    244,408    208,788    193,157    277,652    260,111
  Long-term obligations..................     84,690     66,117     64,351     49,085     46,293     85,700     69,924
  Stockholders' equity...................    117,284    107,712    133,723    120,929    117,368    124,172    111,361
<FN>
- ------------------------------
(1)  P-B changed its year end  from a calendar year end  to a fiscal year  ended
     January  31, effective February 1, 1992. The one month period ended January
     31, 1992  (transition period)  was audited.  Selected historical  financial
     data  for the transition period are  as follows: net revenue $19.7 million,
     loss from operations $1.5 million,  net loss from operations $2.2  million,
     net loss from operations per share of $0.20 and 11.6 million shares used to
     compute net loss from operations per share. No cash dividends were declared
     or paid with respect to the transition period.
(2)  P-B  accrued  restructuring  charges totaling  approximately  $43.2 million
     during the fiscal year ended January 31, 1994.
</TABLE>

                                       7
<PAGE>
SUMMARY UNAUDITED PRO FORMA COMBINED CONDENSED FINANCIAL DATA

    The following summary unaudited pro forma combined condensed financial  data
are derived from the unaudited pro forma combined condensed financial statements
and  notes thereto, appearing elsewhere herein,  which give effect to the Merger
as a pooling of interests, and should be read in conjunction with such unaudited
pro forma statements  and notes  thereto and the  separate audited  consolidated
financial  statements and related notes thereto of Nellcor and P-B, incorporated
by reference  in  this  Proxy Statement/Prospectus.  See  "Unaudited  Pro  Forma
Combined  Condensed Financial Statements." For the  purpose of the unaudited pro
forma combined statement of operations  data, Nellcor's financial data for  each
of  the three fiscal  years in the period  ended July 3,  1994 and the unaudited
nine months ended April 2, 1995 and April 3, 1994 have been combined with  P-B's
financial  data for each of the two fiscal years in the period ended January 31,
1994, the year ended December 31, 1991 and the unaudited nine months ended April
30, 1995 and  1994, respectively.  For the purpose  of the  unaudited pro  forma
combined  balance sheet  data, Nellcor's  financial data  at April  2, 1995 were
combined with P-B's financial data at April 30, 1995.

    The unaudited pro  forma information is  presented for comparative  purposes
only and does not purport to be indicative of the operating results or financial
position  that would  have occurred  if the Merger  had been  consummated at the
beginning of the periods, nor is such information necessarily indicative of  the
future operating results or financial position of Nellcor and P-B.

         SUMMARY UNAUDITED PRO FORMA COMBINED CONDENSED FINANCIAL DATA
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
<TABLE>
<CAPTION>
                                                            FISCAL YEAR ENDED               NINE MONTHS ENDED
                                                  -------------------------------------  ------------------------
                                                    JULY 3,      JULY 4,      JULY 5,     APRIL 2,     APRIL 3,
                                                    1994(1)       1993         1992         1995        1994(1)
                                                  -----------  -----------  -----------  -----------  -----------
<S>                                               <C>          <C>          <C>          <C>          <C>
PRO FORMA COMBINED STATEMENT OF OPERATIONS DATA:
Net revenue.....................................  $   544,227  $   518,246  $   452,286  $   446,884  $   406,265
Income from operations..........................        7,710       58,962       31,428       55,147        2,878
Net income/(loss) from operations...............       (6,422)      39,715       21,867       35,107         (474)
Net income/(loss) from operations per share.....        (0.23)        1.46         0.83         1.26        (0.02)
Shares used to compute net income/ (loss) from
 operations per share...........................       27,364       27,140       26,504       27,961       27,797

<CAPTION>

                                                   APRIL 2,
                                                     1995
                                                  -----------
<S>                                               <C>          <C>          <C>          <C>          <C>
PRO FORMA COMBINED BALANCE
 SHEET DATA:
Working capital.................................  $   251,802
Total assets....................................      550,910
Long-term obligations...........................       85,700
Stockholders' equity............................      343,212
<FN>
- ------------------------

(1)  P-B  accrued  restructuring  charges totaling  approximately  $43.2 million
     during the fiscal year ended January 31, 1994, of which approximately $34.2
     million was accrued during the nine month period ended April 30, 1994.
</TABLE>

                                       8
<PAGE>
COMPARATIVE PER SHARE DATA

    The following table  presents historical, unaudited  pro forma combined  and
unaudited  pro forma equivalent per  share data of Nellcor  and P-B after giving
effect to  the Merger  using  the pooling  of  interests method  of  accounting,
assuming  the Merger  had been effective  during all periods  presented. The pro
forma equivalent data for  P-B have been calculated  by multiplying the  Nellcor
pro  forma combined amounts by the Exchange Ratio of 0.88. The pro forma data do
not purport to be indicative of the results of future operations or the  results
that would have occurred had the Merger been consummated at the beginning of the
periods presented. The information set forth below should be read in conjunction
with  the historical financial  statements and notes thereto  of Nellcor and P-B
incorporated by reference in this Proxy Statement/Prospectus, and the  unaudited
pro  forma combined  condensed financial  statements included  elsewhere in this
Proxy Statement/Prospectus.

    The unaudited  pro forma  combined and  unaudited pro  forma equivalent  per
share  data combine  Nellcor's historical results  for each of  the three fiscal
years in the period ended July 3, 1994 and the unaudited nine months ended April
2, 1995 with  the P-B results  for each of  the two fiscal  years in the  period
ended  January 31, 1994, the year ended December 31, 1991 and the unaudited nine
months ended April 30, 1995,  respectively, and Nellcor's financial position  at
April 2, 1995 with P-B's financial position at April 30, 1995.

<TABLE>
<CAPTION>
                                                                                                            NINE MONTHS
                                                                               FISCAL YEAR ENDED               ENDED
                                                                      -----------------------------------  --------------
                                                                       JULY 3,     JULY 4,      JULY 5,       APRIL 2,
                                                                        1994        1993         1992           1995
                                                                      ---------  -----------  -----------  --------------
<S>                                                                   <C>        <C>          <C>          <C>
NELLCOR COMMON STOCK
Net income/(loss) from operations per share:
  Historical........................................................  $    1.22   $    1.50    $    1.31     $     1.51
  Pro forma combined................................................  $   (0.23)  $    1.46    $    0.83     $     1.26
Cash dividend per share:
  Historical........................................................     --          --           --             --
Book value per share at period end:
  Historical........................................................  $   12.12      n/a          n/a        $    13.34
  Pro forma combined................................................  $   11.57      n/a          n/a        $    12.27

P-B COMMON STOCK
Net income/(loss) from operations per share:
  Historical........................................................  $   (2.66)  $    1.24    $    0.05     $     0.54
  Pro forma equivalent..............................................  $   (0.20)  $    1.28    $    0.73     $     1.11
Cash dividend per share:
  Historical........................................................  $    0.12   $    0.12    $    0.12     $     0.09
  Pro forma equivalent..............................................     --          --           --             --
Book value per share at period end:
  Historical........................................................  $    9.01      n/a          n/a        $     9.84
  Pro forma equivalent..............................................  $   10.18      n/a          n/a        $    10.80
</TABLE>

                                       9
<PAGE>
                           INVESTMENT CONSIDERATIONS

    The  following factors should be considered carefully by the stockholders of
Nellcor and P-B in connection with voting on the matters to be presented at  the
Special Meetings.

INTEGRATION OF THE BUSINESSES

    The  Merger involves the  integration of two  companies that have previously
operated independently. Among the  factors considered by  the Nellcor Board  and
P-B  Board in connection  with their approval  of the Merger  Agreement were the
opportunities for operating efficiencies that they expect will ultimately result
from the  Merger. The  integration of  the companies'  operations following  the
Merger  will require the dedication of substantial management resources in order
to achieve the anticipated operating  efficiencies of the Merger. While  Nellcor
and  P-B expect to achieve savings in operating costs as a result of the Merger,
no assurance  can be  given  that difficulties  encountered in  integrating  the
operations  of Nellcor and  P-B will be  overcome or that  the benefits expected
from such  integration  will be  realized.  The difficulties  of  combining  the
companies'   operations  are  exacerbated  by   the  necessity  of  coordinating
geographically separated  organizations,  integrating personnel  with  disparate
business  backgrounds and combining different corporate cultures. The process of
integrating operations could cause an interruption  of, or loss of momentum  in,
the  activities of  either or  both of  the companies'  businesses. Difficulties
encountered in  connection  with the  Merger  and  the integration  of  the  two
companies'  operations could have an adverse  effect on the business, results of
operations or financial condition of the combined companies.

    Subsequent to the Merger, Nellcor expects  to incur a charge in the  quarter
ended  October 1, 1995, currently estimated to be in the range of $20 million to
$30 million, to reflect  the combination of the  two companies, including  costs
relating  to  severance and  employee relocation,  the elimination  of duplicate
systems and facilities and other integration costs. This amount is a preliminary
estimate only and is therefore subject to  change. In addition, there can be  no
assurance  that Nellcor will not incur additional charges in subsequent quarters
to reflect costs associated with the Merger.

HEALTH CARE REFORM/PRICING PRESSURE

    The health care industry  in the United States  is experiencing a period  of
extensive change. Changes in the law or new interpretations of existing laws may
have  a  dramatic  effect  on the  definition  of  permissible  or impermissible
activities, the relative costs associated with doing business and the amount  of
reimbursement  by both government and  third-party payors. In addition, economic
forces, regulatory  influences  and  political initiatives  are  subjecting  the
health  care industry to  fundamental change. Health  care reform proposals have
been formulated by  the current administration  and by members  of Congress.  In
addition,  state legislatures  periodically consider various  health care reform
proposals. Federal,  state and  local government  representatives will,  in  all
likelihood,  continue  to review  and  assess alternative  health  care delivery
systems and payment methodologies, and ongoing public debate of these issues can
be  expected.  Currently,  the  health   care  industry  also  is   experiencing
market-driven reforms from forces within the industry that are exerting pressure
on  health  care  companies to  reduce  health care  costs.  These market-driven
reforms are  resulting  in  industry-wide  consolidation  that  is  expected  to
increase  the downward pressure on health  care product margins, as larger buyer
and supplier groups exert pricing pressure  on providers of medical devices  and
other health care products. The ultimate timing or effect of legislative efforts
and  market driven reforms cannot be  predicted, and short-term cost containment
initiatives may vary  substantially from  long-term reforms and  may impact  the
combined  business of  Nellcor and  P-B in different  ways. No  assurance can be
given that any such efforts or reforms  will not have a material adverse  effect
on  the business, results  of operations or financial  condition of the combined
companies.

DEPENDENCE ON THIRD PARTIES; MANAGED CARE ORGANIZATIONS

    The businesses of Nellcor and P-B depend upon relationships with  hospitals,
hospital   groups,   purchasing  organizations,   managed   care  organizations,
physicians, physician  groups, home  health care  organizations, long-term  care
facilities,  private and governmental third party payors and other institutional
health care providers.  There can be  no assurance that  the combined  companies
will be

                                       10
<PAGE>
able  successfully to  maintain and develop  the third  party relationships that
will be required  after the Merger,  or that certain  relationships will not  be
adversely   affected  by  the  Merger.  The   loss  of  or  damage  to  existing
relationships, or  the failure  to continue  to develop  relationships of  these
kinds,  could  have  a  material  adverse effect  on  the  business,  results of
operations and financial condition of the combined companies after the Merger.

    Managed  care  organizations  have  grown  substantially  in  terms  of  the
percentage of the population in the United States that receives medical benefits
through  such organizations and in terms of  the influence and control that such
organizations are able to exert over an increasingly large portion of the health
care industry. Managed  care organizations  are continuing  to consolidate,  and
such  consolidation may increase the ability  of such organizations to influence
the practices and pricing involved in the purchase of medical devices, including
those sold by Nellcor and P-B.

GOVERNMENT REGULATION

    The United  States  Food  and  Drug  Administration  ("FDA")  regulates  the
development,  testing, manufacturing,  packaging, distribution  and marketing of
medical devices in the United States, including the products manufactured by P-B
and Nellcor. Comparable agencies in certain foreign countries also regulate  the
activities of P-B and Nellcor.

    GENERAL.   The development,  testing, manufacturing, packaging, distribution
and marketing of medical  devices in the United  States are regulated under  the
Medical  Device Amendments of 1976  to the Federal Food,  Drug, and Cosmetic Act
(the "1976  Amendments"), the  Safe Medical  Devices Act  of 1990,  the  Medical
Device Amendments of 1992 and additional regulations promulgated by the FDA. The
State  of California, where  both Nellcor and P-B  have manufacturing plants, as
well as other states, also regulate the manufacture of medical devices.

    In general, these statutes and regulations require that manufacturers adhere
to certain standards designed to ensure the safety and effectiveness of  medical
devices. Under the 1976 Amendments, each medical device manufacturer must comply
with  statutes and regulations applicable  generally to manufacturing practices,
clinical investigations involving humans, sale and marketing of medical devices,
post-market surveillance, repairs, replacements and refunds, recalls, and  other
matters.  The FDA is authorized to obtain and inspect devices and their labeling
and advertising, and to inspect the facilities in which they are manufactured in
order to ensure that a device is not improperly manufactured or labeled.

    REGULATION OF NEW PRODUCTS.  The FDA requires that a new medical device or a
new indication for  use of or  other significant change  in an existing  medical
device  obtain  either 510(k)  premarket notification  clearance or  an approved
Premarket Approval Application ("PMA") prior to being introduced into the market
in the United  States. The  process of obtaining  510(k) clearance  may take  at
least  six  months from  the date  of  filing of  the application  and generally
requires the submission of  supporting data, which can  be extensive and  extend
the  process for a considerable length of time. In addition, the FDA may require
review by an  advisory panel  as a condition  for 510(k)  clearances, which  can
further  lengthen the  process. The  PMA process  generally takes  more than two
years from initial filing  and requires the  submission of extensive  supporting
data  and clinical information. In recent years,  there has been a trend for the
FDA to  require more  supporting  data with  respect  to both  510(k)  clearance
notifications  and PMA filings. Historically,  substantially all of the products
of Nellcor and P-B  have been submitted  to the FDA  under the 510(k)  premarket
notification clearance process. However, as the combined companies broaden their
product  base, new  products could  be required  to be  submitted under  the PMA
process rather than the 510(k) process.

    FOREIGN REGULATION.  Sales of medical devices outside the United States  are
subject  to foreign  regulatory requirements  that vary  widely from  country to
country. The  time required  to  obtain clearance  to  sell medical  devices  in
foreign countries may be longer or shorter than that required for FDA clearance,
and  requirements for licensing may  differ significantly from FDA requirements.
Some countries have historically permitted human studies earlier in the  product
development cycle than

                                       11
<PAGE>
regulations in the United States. Other countries, such as Japan, have standards
similar to those of the FDA. This disparity in the regulation of medical devices
may  result in  more rapid  product clearance in  certain countries  than in the
United States, while  clearance in countries  such as Japan  may require  longer
periods than in the United States. In addition, the European Union has developed
a  new approach  to the  regulation of  medical products  that may significantly
change the situation in those countries. The receipt or denial of FDA  clearance
for  a  particular  product  may  affect the  receipt  or  denial  of regulatory
clearance for that product in certain other countries.

    GMP REQUIREMENTS;  FDA  ENFORCEMENT.    The  1976  Amendments  also  require
compliance   with  specific  manufacturing   and  quality  assurance  standards,
including regulations promulgated by the FDA with respect to good  manufacturing
practices.  FDA regulations require  that each manufacturer  establish a quality
assurance program by which the  manufacturer monitors the manufacturing  process
and  maintains records  that show  compliance with  the FDA  regulations and the
manufacturer's written specifications  and procedures relating  to the  devices.
Compliance  with  the good  manufacturing practices  regulation is  necessary to
receive FDA approval to market new products and is necessary for a  manufacturer
to be able to continue to market approved product offerings.

    The  FDA makes unannounced  inspections of medical  device manufacturers and
may issue reports of  observations where the manufacturer  has failed to  comply
with  all  appropriate  regulations  and  procedures.  Failure  to  comply  with
applicable regulatory  requirements can,  among  other consequences,  result  in
warning   letters,  civil  penalties,  injunctions,  suspensions  or  losses  of
regulatory clearances, product recalls,  seizure or administrative detention  of
products,  operating restrictions through consent  decrees or otherwise, refusal
of  the  government  to  approve   product  license  applications  or  allow   a
manufacturer to enter into supply contracts, and criminal prosecution.

    There has been a trend in recent years both in the United States and outside
the  United  States  toward more  stringent  regulation of,  and  enforcement of
requirements applicable to, medical  device manufacturers. The continuing  trend
of  more  stringent regulatory  oversight in  product clearance  and enforcement
activities has caused medical device manufacturers to experience longer approval
cycles, more uncertainty, greater risk and higher expenses. At the present time,
there are no meaningful indications that this trend will be discontinued in  the
near-term or the long-term either in the United States or abroad.

    FDA  ENFORCEMENT WITH RESPECT TO  P-B.  P-B has  been subject to significant
FDA enforcement activity  with respect  to its  operations in  recent years.  In
January  1994, P-B entered into a consent  decree with the FDA pursuant to which
P-B agreed to  maintain systems  and procedures  complying with  the FDA's  good
manufacturing  practices regulation  and medical device  reporting regulation in
all of its device manufacturing facilities. Under the decree, domestic shipments
of P-B's portable  ventilator products and  intra-arterial blood gas  monitoring
systems  were  suspended  until  the  FDA  could  become  satisfied  with  P-B's
manufacturing practices  for such  products.  Both Burton  A. Dole,  Jr.,  P-B's
Chairman,  President  and  Chief  Executive Officer,  and  John  H.  Morrow, its
Executive Vice President and Chief Operating Officer, are parties to the consent
decree. Under the terms of the  Merger Agreement, following consummation of  the
Merger,  Mr. Dole will be the Chairman of the Board of Directors of the combined
companies and  Mr. Morrow  will  be Executive  Vice  President of  the  combined
companies  and President of  the combined companies'  Home Health Care Business.
See "The Merger -- Management After the Merger."

    As a result  of the  consent decree, P-B  curtailed operations  of its  FOxS
intra-arterial  blood gas monitoring  systems division in  the fourth quarter of
fiscal year 1994 pending location of a purchaser of the division or a  strategic
partner  that might  be able  to assist  P-B with  respect to  its operation. No
partner was found for the FOxS division. P-B then closed the FOxS division.

    In addition, as a result of  the consent decree, P-B suspended shipments  of
portable  ventilators from  its Boulder, Colorado  facility to  customers in the
United States. P-B then  closed the Boulder, Colorado  facility and shifted  all
manufacturing  of portable ventilators  to facilities outside  the United States
from which P-B continues to serve markets outside the United States.

                                       12
<PAGE>
    P-B incurred restructuring  charges of  approximately $43.2  million in  its
fiscal  year 1994, primarily as  a result of the  shut-down of the FOxS business
described above, the closure of its Boulder, Colorado facility and the cessation
of its portable ventilator manufacturing in the United States.

    Under the terms of the consent decree, P-B must notify the FDA of the Merger
at least 10 days prior to consummation of the Merger.

    IMPACT OF P-B  CONSENT DECREE.   P-B has  experienced and  will continue  to
experience  incremental operating  costs due to  ongoing compliance requirements
and quality assurance programs initiated in part as a result of the FDA  consent
decree.   P-B  expects  to  continue  to  incur  additional  operating  expenses
associated with its  ongoing regulatory  compliance program, but  the amount  of
these  incremental costs  cannot be completely  predicted at this  time and will
depend upon  a variety  of factors,  including future  changes in  statutes  and
regulations  governing medical device manufacturers and  the manner in which the
FDA continues to enforce and interpret the requirements of the consent decree.

    POSSIBLE IMPACT ON COMBINED COMPANIES.   There can be no assurance that  the
combined  companies will not experience  problems associated with FDA regulatory
compliance after  the  Merger,  including increased  general  costs  of  ongoing
regulatory compliance and specific costs associated with the P-B consent decree.
The  combined companies could experience a  material adverse effect on business,
operations, profitability and outlook from, among other things: (i) requirements
associated  with  the  P-B  consent  decree;  (ii)  requirements  arising   from
continuing  company-wide adherence  to quality assurance  and good manufacturing
practices; (iii) the  results of future  FDA inspections of  the operations  and
facilities  of  the  combined  companies; (iv)  any  modification,  extension or
adverse interpretation of the  P-B consent decree or  any product recall,  plant
closure  or  other  FDA  enforcement  activity  with  respect  to  the  combined
companies; and (v) any  failure by the combined  companies in obtaining, or  any
delay in obtaining, required product approvals.

DEPENDENCE OF EARNINGS ON CERTAIN PRODUCTS

    For  its fiscal year ended July 3, 1994  and for the nine months ended April
2, 1995, more  than three-quarters  of Nellcor's revenues  were attributable  to
sales  of its oximetry products, which include oximetry instruments, sensors and
OEM modules. On a pro forma  basis, such oximetry products would have  accounted
for  approximately 38% of the  revenues of the combined  companies, and a higher
percentage of  their  combined  earnings,  for the  year  ended  July  3,  1994.
Accordingly,  negative developments in the  market for, or Nellcor's competitive
position with respect to,  its oximetry products could  have a material  adverse
effect  on the  business, results  of operations  or financial  condition of the
combined companies.

INTELLECTUAL PROPERTY RIGHTS

    From time to  time, Nellcor and  P-B have  received, and in  the future  may
receive,  notices  of  claims  with  respect  to  possible  infringement  of the
intellectual property  rights  of  others  or notices  of  challenges  to  their
respective  intellectual property  rights. In  some instances  such notices have
given rise to,  or may give  rise to, litigation.  Any litigation involving  the
intellectual  property rights of  Nellcor or P-B  may be resolved  by means of a
negotiated settlement or by contesting the claim through the judicial process.

    In December 1992,  Nellcor commenced  an action in  Alameda County  Superior
Court,  Eastern  Division, State  of California  against  BOC Health  Care, Inc.
("BOC"), the parent  corporation of  Ohmeda Inc. ("Ohmeda"),  and certain  other
parties  for, among other  things, misappropriation of  trade secrets and unfair
competition. BOC  in turn  commenced an  action against  Nellcor in  the  United
States  District  Court for  the District  of  Delaware (the  "Delaware District
Court") seeking a declaratory  judgment that certain  of Nellcor's patents  were
invalid  and/or not infringed by  the manufacture, use or  sale of the BOC pulse
oximetry sensor which was  the subject matter of  the California Superior  Court
action  by Nellcor. In the third quarter  of fiscal year 1994, Nellcor agreed to
settle the trade  secrets litigation  with BOC and  the other  named parties  on
terms  which provided  for the payment  to Nellcor  of an initial  royalty of $2
million  plus  ongoing  royalties   and  the  assignment   to  Nellcor  of   the

                                       13
<PAGE>
patent  at issue in the case. In July 1995, the Delaware District Court issued a
decision in favor of Nellcor ruling that four key oximeter and sensor technology
patents are valid and would be infringed by Ohmeda if Ohmeda sold certain  pulse
oximetry  sensors for  use with non-Ohmeda  monitors. Although  Nellcor has been
successful to  date in  its litigation  with BOC  and Ohmeda,  there can  be  no
assurance that the decision of the Delaware District Court will not be appealed.

    Neither  Nellcor nor P-B believes that the  outcome of the BOC litigation or
any currently  pending  claims  will  have a  material  adverse  effect  on  the
financial  position or results of operations of the combined companies after the
Merger. There  can  be  no assurance  that  the  results of  operations  or  the
financial condition of the combined companies will not suffer a material adverse
effect as a result of intellectual property claims that may be commenced against
Nellcor or P-B in the future.

COMPETITION

    The  medical device industry is characterized by rapidly evolving technology
and increased competition. Competitors of P-B and Nellcor include large  medical
companies,  some of  which have  greater financial  and technical  resources and
broader product lines than  Nellcor and P-B, even  on a combined basis.  Nellcor
and  P-B  believe that  the principal  competitive  factors in  their respective
markets are  product features,  price, quality,  customer service,  performance,
market  reputation, breadth of product offerings  and effectiveness of sales and
marketing efforts. There are a number of companies that currently offer, or  are
in  the process  of developing, products  that compete with  products offered by
Nellcor and  P-B.  Some of  these  competitors may  have  substantially  greater
capital resources, research and development staffs and experience in the medical
device  industry,  including  with  respect  to  regulatory  compliance  in  the
development, manufacturing and sale of medical products similar to those offered
by Nellcor and P-B.  There can be  no assurance that  some of these  competitors
will not succeed in developing technologies and products that are more effective
than  those currently used or  produced by Nellcor and  P-B or that would render
some  products  offered  by  Nellcor   and  P-B  obsolete  or   non-competitive.
Competition  based  on price  is expected  to  become an  increasingly important
factor in customer purchasing patterns as a result of cost containment pressures
on, and  consolidation  in,  the  health care  industry.  Such  competition  has
exerted,  and is likely  to continue to  exert, downward pressure  on the prices
Nellcor and P-B are able to charge for their products. There can be no assurance
that the combined companies will be able to offset such downward price  pressure
through corresponding cost reductions. Any failure to offset such pressure could
have  a  material  adverse effect  on  the  business, results  of  operations or
financial condition of the combined companies.

NEW PRODUCT INTRODUCTIONS

    As the existing  products of Nellcor  and P-B become  more mature and  their
existing  markets more  saturated, the importance  to the  combined companies of
developing or acquiring new products will increase. The development of any  such
products  will  entail considerable  time  and expense,  including  research and
development costs  and  the  time  and  expense  required  to  obtain  necessary
regulatory  approvals,  which could  adversely affect  the business,  results of
operations or financial  condition of the  combined companies. There  can be  no
assurance  that  such development  activities will  yield  products that  can be
commercialized profitably, or that any  product acquisitions can be  consummated
on  commercially reasonable terms or  at all. Any failure  to acquire or develop
new products to supplement more mature products could have an adverse effect  on
the  business,  results of  operations or  financial  condition of  the combined
companies.

PRODUCT LIABILITY EXPOSURE

    Because the products  of both Nellcor  and P-B  are intended to  be used  in
health  care settings on patients who  are physiologically unstable and may also
be seriously or critically ill, both companies are exposed to potential  product
liability  claims. Furthermore,  P-B faces  potential product  liability risk in
connection with the operations of  Aero Systems, which principally develops  and
manufactures  emergency oxygen systems  for use on aircraft.  From time to time,
patients using Nellcor or  P-B products have suffered  serious injury or  death,
which  has led to product liability claims against both Nellcor and P-B. Neither
company believes that  any of these  claims, individually or  in the  aggregate,
will have

                                       14
<PAGE>
a  material adverse effect  on its business, results  of operations or financial
condition. There can be no assurance, however,  that Nellcor or P-B will not  in
the  future  be subject  to  product liability  claims  that could  have  such a
material adverse effect.

    Both Nellcor  and  P-B  maintain product  liability  insurance  coverage  in
amounts  that each deems sufficient for  its respective business. However, there
can be no assurance that such coverage will ultimately prove to be adequate,  or
that  such coverage will continue to remain  available on acceptable terms or at
all.

DEPENDENCE ON KEY PERSONNEL

    After the Merger, the combined companies will be dependent on the  continued
services  and  management  experience  of  their  executive  officers.  If  such
executive officers  were  to  leave,  the  operating  results  of  the  combined
companies  could be adversely affected. In addition, the continued growth of the
combined companies  will  depend  on  the ability  of  their  officers  and  key
employees to manage growth successfully.

EMPLOYEES

    Many  of the employees of Nellcor and P-B are highly skilled. Competition in
recruiting and retaining such personnel is intense in the labor markets in which
Nellcor  and  P-B  operate.  Locating  persons  with  experience  in   regulated
industries is particularly difficult. The success of Nellcor and P-B, as well as
that of the combined companies, is predicated in part on the ability to continue
to  attract, retain and motivate highly qualified management, marketing, medical
and technical personnel.

IMPACT OF CURRENCY FLUCTUATIONS; IMPORTANCE OF FOREIGN SALES

    Because sales  of products  by Nellcor  and P-B  outside the  United  States
typically are denominated in local currencies and such sales by both Nellcor and
P-B  are growing  at a rate  that is  generally faster than  domestic sales, the
results of operations of the combined  companies are expected to continue to  be
affected by changes in exchange rates between certain foreign currencies and the
United States dollar. There can be no assurance that the combined companies will
not  experience currency fluctuation effects in future periods, which could have
an adverse effect on  the operating results of  the combined companies.  Nellcor
currently  engages  in some  hedging activities,  while  P-B does  not currently
engage in any material currency hedging activities. The operations and financial
results of the combined  companies also may be  significantly affected by  other
international  factors, including changes in  governmental regulations or import
and  export  restrictions,  and   foreign  economic  and  political   conditions
generally.

POSSIBLE VOLATILITY OF STOCK PRICE

    The  market price of Nellcor Common Stock is, and is expected to continue to
be, subject to significant fluctuations  in response to variations in  quarterly
operating results, trends in the health care industry in general and the medical
device  industry in particular, and certain  other factors beyond the control of
Nellcor. In addition, broad market fluctuations, as well as general economic  or
political  conditions and initiatives such as  health care reform, may adversely
affect the market  price of Nellcor  Common Stock, regardless  of the  operating
performance of the combined companies.

CERTAIN ANTI-TAKEOVER PROVISIONS

    The  Nellcor  Rights  Agreement  and  certain  provisions  of  the  Restated
Certificate of  Incorporation of  Nellcor,  including provisions  requiring  the
affirmative  vote of the holders of at least  66 2/3% of the voting power of the
then outstanding shares of Nellcor capital  stock entitled to vote generally  in
the  election  of  directors  to  approve  certain  business  combinations  with
interested persons, may make  an unsolicited acquisition  of control of  Nellcor
more  difficult or expensive than would  otherwise be the case. See "Description
of Capital Stock of Nellcor" and "Comparison of Stockholder Rights."

                                       15
<PAGE>
DIVIDEND POLICY

    Nellcor has never paid  any cash dividends, and  does not anticipate  paying
cash  dividends  in the  foreseeable future  following the  Merger. Accordingly,
holders of P-B Common Stock, who presently receive a quarterly dividend of $0.03
per share, will  cease receiving  such dividends following  the Merger.  Pending
consummation  of the Merger, P-B has agreed  to cease paying dividends after its
May 1995 regular cash dividend. See "The Merger Agreement -- Certain Covenants."

                          THE NELLCOR SPECIAL MEETING

PURPOSE OF THE NELLCOR SPECIAL MEETING

    At the  Nellcor  Special  Meeting,  holders of  Nellcor  Common  Stock  will
consider  and  vote upon  proposals to  approve  (i) the  issuance of  shares of
Nellcor Common  Stock  pursuant to  the  Merger Agreement  (the  "Nellcor  Share
Proposal"), (ii) an amendment to Nellcor's Restated Certificate of Incorporation
to  change Nellcor's corporate name to Nellcor Puritan Bennett Incorporated (the
"Nellcor Charter  Amendment Proposal");  (iii) the  adoption of  Nellcor's  1995
Merger Stock Incentive Plan (the "1995 Plan Proposal"); and (iv) the adoption of
an  amendment to Nellcor's 1994 Equity Incentive  Plan to increase the number of
shares of Nellcor  Common Stock  available for grant  thereunder from  1,500,000
shares  to  2,500,000  shares  (the  "1994  Plan  Amendment  Proposal").  For  a
description of the  Nellcor Share  Proposal, see  "The Merger"  and "The  Merger
Agreement."  For a  description of the  Nellcor Charter  Amendment Proposal, see
"Proposed Amendment to Nellcor's Restated  Certificate of Incorporation." For  a
description  of the 1995 Plan Proposal and the 1994 Plan Amendment Proposal, see
"The Nellcor 1995 Merger Stock Incentive  Plan" and "The Amendment to  Nellcor's
1994  Equity Incentive  Plan," respectively.  Stockholders of  Nellcor will also
consider and vote on any other matter that may properly come before the meeting.

    Neither the DGCL nor  the Restated Certificate  of Incorporation of  Nellcor
requires  Nellcor to obtain  stockholder approval of the  Merger, because P-B is
merging with Sub, a wholly-owned subsidiary of Nellcor, rather than with Nellcor
itself. However, due  to the  number of  shares of  Nellcor Common  Stock to  be
issued  in  the  Merger,  Nasdaq rules  require  Nellcor  to  obtain stockholder
approval of the  issuance of such  shares. Stockholder approval  of the  Nellcor
Share  Proposal will constitute the approval required by Nasdaq for the issuance
of the Nellcor Common Stock in connection with the Merger. Stockholder  approval
of  the Nellcor Charter Amendment Proposal  is required by the DGCL. Stockholder
approval of  the  1995  Plan Proposal  is  being  sought so  as  to  assure  the
availability  of the exemption under Rule  16b-3, promulgated under the Exchange
Act, to stock options granted pursuant to such plan. Stockholder approval of the
1994 Plan  Amendment Proposal  is  also being  sought  to assure  the  continued
availability  of the  exemption under Rule  16b-3 to stock  awards granted under
such plan.

    THE  NELLCOR  BOARD  HAS  UNANIMOUSLY  APPROVED  THE  TERMS  OF  THE  MERGER
AGREEMENT,  BELIEVES THAT THE TERMS OF THE  MERGER AGREEMENT ARE FAIR TO, AND IN
THE BEST INTERESTS OF, NELLCOR AND ITS STOCKHOLDERS, AND UNANIMOUSLY  RECOMMENDS
THAT  HOLDERS  OF SHARES  OF NELLCOR  COMMON  STOCK VOTE  "FOR" APPROVAL  OF THE
NELLCOR SHARE PROPOSAL, THE  NELLCOR CHARTER AMENDMENT  PROPOSAL, THE 1995  PLAN
PROPOSAL AND THE 1994 PLAN AMENDMENT PROPOSAL.

RECORD DATE; VOTING RIGHTS; PROXIES

    Only  holders of Nellcor Common  Stock at the close  of business on July 14,
1995 (the "Nellcor Record Date")  are entitled to notice of  and to vote at  the
Nellcor Special Meeting.

   
    As  of  the Nellcor  Record Date,  there were  16,712,444 shares  of Nellcor
Common Stock issued and outstanding, each  of which entitled the holder  thereof
to one vote.
    

    All  shares of Nellcor Common Stock represented by properly executed proxies
will, unless such proxies have been  previously revoked, be voted in  accordance
with  the  instructions  indicated  in  such  proxies.  IF  NO  INSTRUCTIONS ARE
INDICATED, SUCH SHARES OF NELLCOR COMMON STOCK WILL BE

                                       16
<PAGE>
VOTED "FOR" THE NELLCOR SHARE PROPOSAL, THE NELLCOR CHARTER AMENDMENT  PROPOSAL,
THE  1995 PLAN PROPOSAL AND  THE 1994 PLAN AMENDMENT  PROPOSAL. Nellcor does not
know of any matters  other than as  described in the  Notice of Special  Meeting
that  are to  come before the  Nellcor Special  Meeting. If any  other matter or
matters are properly presented  for action at the  Nellcor Special Meeting,  the
persons  named in the enclosed form of proxy and acting thereunder will have the
discretion to vote  on such matters  in accordance with  their best judgment.  A
stockholder  who  has given  a proxy  may revoke  it  at any  time prior  to its
exercise by  giving written  notice  thereof to  the  Secretary of  Nellcor,  by
signing and returning a later dated proxy, or by voting in person at the Nellcor
Special  Meeting. However, mere  attendance at the  Nellcor Special Meeting will
not in and of itself have the effect of revoking the proxy. Votes cast by  proxy
or  in person at the Nellcor Special  Meeting will be tabulated by the inspector
of election appointed for the meeting.

SOLICITATION OF PROXIES

    Proxies are being solicited by and  on behalf of the Nellcor Board.  Nellcor
will  bear all  expenses in  connection with  such solicitation.  In addition to
solicitation by  use  of the  mails,  proxies  may be  solicited  by  directors,
officers  and employees of Nellcor in person  or by telephone, telegram or other
means of  communication. Such  directors,  officers and  employees will  not  be
additionally  compensated for, but may  be reimbursed for out-of-pocket expenses
incurred in connection with, such solicitation. Arrangements have also been made
with brokerage  firms,  banks,  custodians, nominees  and  fiduciaries  for  the
forwarding of proxy and solicitation materials to owners of Nellcor Common Stock
held  of record by such persons, and  in connection therewith such firms will be
reimbursed for  reasonable  expenses  incurred  in  forwarding  such  materials.
Nellcor  and P-B have  each retained Corporate  Investor Communications, Inc. to
aid in  the solicitation  of  proxies from  their respective  stockholders.  The
aggregate   fees  of  such  firm  for  the  solicitation  of  proxies  from  the
stockholders of Nellcor and P-B are  estimated to be $15,000 plus  reimbursement
of out-of-pocket expenses.

QUORUM

    The  presence  in person  or  by properly  executed  proxy of  holders  of a
majority of all  of the issued  and outstanding shares  of Nellcor Common  Stock
entitled  to vote  is necessary  to constitute a  quorum at  the Nellcor Special
Meeting. For purposes of determining whether a quorum is present, the  inspector
of  election will include shares the holders of which abstain from voting on any
particular matter ("abstentions") and exclude shares that are held of record  by
brokers   and  as  to  which  such  brokers  indicate  that  they  do  not  have
discretionary authority to vote on any particular matter ("broker non-votes").

REQUIRED VOTE

    Approval of the Nellcor  Share Proposal requires the  affirmative vote of  a
majority  of  the total  votes  cast on  such  proposal at  the  Nellcor Special
Meeting. Approval  of  the  Nellcor  Charter  Amendment  Proposal  requires  the
affirmative  vote of  the holders  of a  majority of  the outstanding  shares of
Nellcor Common Stock entitled  to vote thereon at  the Nellcor Special  Meeting.
Approval of the 1995 Plan Proposal and the 1994 Plan Amendment Proposal requires
the  affirmative vote  of the  holders of  a majority  of the  shares of Nellcor
Common Stock  present, or  represented,  and entitled  to  vote at  the  Nellcor
Special  Meeting. Approval of  the Nellcor Charter  Amendment Proposal, the 1995
Plan Proposal and the  1994 Plan Amendment  Proposal is not  a condition to  the
consummation  of the Merger,  but such proposals will  not be implemented unless
the Merger is consummated. However, Nellcor is obligated under the terms of  the
Merger  Agreement  to  implement  the  1995  Plan  Proposal  if  the  Merger  is
consummated, whether or not  stockholder approval of the  1995 Plan Proposal  is
obtained.

    For  purposes of  determining whether  the Nellcor  Share Proposal  has been
approved,  the  inspector  of  election  will  exclude  abstentions  and  broker
non-votes  from the number of shares deemed to  have voted on such matter at the
Nellcor Special Meeting. Accordingly, abstentions and broker non-votes will  not
affect  the voting  on the Nellcor  Share Proposal. For  purposes of determining
whether the Nellcor Charter Amendment Proposal has been approved, the  inspector
of  election  will include  abstentions and  broker non-votes  in the  number of
outstanding shares of Nellcor Common Stock

                                       17
<PAGE>
entitled  to  vote  thereon  at   the  Nellcor  Special  Meeting.   Accordingly,
abstentions  and broker  non-votes will have  the effect  of a "NO"  vote on the
Nellcor Charter Amendment Proposal. For purposes of determining whether the 1995
Plan Proposal  and the  1994 Plan  Amendment Proposal  have been  approved,  the
inspector  of election will  include abstentions, but  exclude broker non-votes,
from the number  of shares  of Nellcor  Common Stock  deemed to  be present,  or
represented,  and entitled to vote at  the Nellcor Special Meeting. Accordingly,
abstentions will have the effect of a "NO" vote, and broker non-votes will  have
no effect, on the 1995 Plan Proposal and the 1994 Plan Amendment Proposal.

    As  of June 30, 1995, directors and  executive officers of Nellcor and their
affiliates were beneficial owners of an  aggregate of 191,934 shares of  Nellcor
Common  Stock  (exclusive of  any  shares issuable  upon  the exercise  of stock
options remaining unexercised as  of such date), or  approximately 1.15% of  the
16,706,250 shares of Nellcor Common Stock that were issued and outstanding as of
such  date. See "Management of Nellcor After the Merger -- Security Ownership of
Management." Each  of  the  directors  and executive  officers  of  Nellcor  has
indicated  an intention to vote all  shares of Nellcor Common Stock beneficially
owned by him  or her in  favor of approval  of the Nellcor  Share Proposal,  the
Nellcor  Charter Amendment  Proposal, the 1995  Plan Proposal and  the 1994 Plan
Amendment Proposal.

    THE MATTERS TO  BE CONSIDERED AT  THE NELLCOR SPECIAL  MEETING ARE OF  GREAT
IMPORTANCE  TO THE STOCKHOLDERS OF  NELLCOR. ACCORDINGLY, STOCKHOLDERS ARE URGED
TO  READ  AND  CAREFULLY  CONSIDER  THE  INFORMATION  PRESENTED  IN  THIS  PROXY
STATEMENT/PROSPECTUS,  AND  TO  COMPLETE,  DATE, SIGN  AND  PROMPTLY  RETURN THE
ENCLOSED PROXY IN THE ENCLOSED POSTAGE-PAID ENVELOPE.

                            THE P-B SPECIAL MEETING

PURPOSE OF THE P-B SPECIAL MEETING

    At the P-B Special  Meeting, holders of P-B  Common Stock will consider  and
vote  upon a proposal to adopt the Merger  Agreement. As a result of the Merger,
P-B will become a wholly-owned subsidiary  of Nellcor. Stockholders of P-B  will
also  consider and vote  on any other  matter that may  properly come before the
meeting.

    THE P-B BOARD HAS  UNANIMOUSLY APPROVED THE TERMS  OF THE MERGER  AGREEMENT,
BELIEVES  THAT THE TERMS  OF THE MERGER AGREEMENT  ARE FAIR TO,  AND IN THE BEST
INTERESTS OF, P-B AND ITS STOCKHOLDERS, AND UNANIMOUSLY RECOMMENDS THAT  HOLDERS
OF SHARES OF P-B COMMON STOCK VOTE "FOR" APPROVAL OF THE MERGER AGREEMENT.

RECORD DATE; VOTING RIGHTS; PROXIES

    Only  holders of P-B Common Stock at the  close of business on July 14, 1995
(the "P-B Record Date") are entitled to notice of and to vote at the P-B Special
Meeting.

    As of the P-B Record Date, there were 12,936,210 shares of P-B Common  Stock
issued and outstanding, each of which entitled the holder thereof to one vote.

    All  shares of  P-B Common  Stock represented  by properly  executed proxies
will, unless such proxies have been  previously revoked, be voted in  accordance
with  the  instructions  indicated  in  such  proxies.  IF  NO  INSTRUCTIONS ARE
INDICATED, SUCH SHARES OF P-B COMMON STOCK WILL BE VOTED IN FAVOR OF ADOPTION OF
THE MERGER AGREEMENT. P-B does not know  of any matters other than as  described
in  the  Notice of  Special  Meeting that  are to  come  before the  P-B Special
Meeting. If any other matter or matters are properly presented for action at the
P-B Special Meeting, the persons named in the enclosed form of proxy and  acting
thereunder  will have the discretion to vote  on such matters in accordance with
their best judgment. A stockholder  who has given a proxy  may revoke it at  any
time  prior to its exercise by giving written notice thereof to the Secretary of
P-B, by signing and returning a later dated proxy, or by voting in person at the
P-B Special Meeting. However, mere

                                       18
<PAGE>
attendance at the P-B Special Meeting will not in and of itself have the  effect
of  revoking the  proxy. Votes  cast by proxy  or in  person at  the P-B Special
Meeting will  be tabulated  by  the inspectors  of  election appointed  for  the
meeting.

SOLICITATION OF PROXIES

    Proxies are being solicited by and on behalf of the P-B Board. P-B will bear
all  expenses in connection with such  solicitation. In addition to solicitation
by use  of  the mails,  proxies  may be  solicited  by directors,  officers  and
employees  of  P-B  in  person  or by  telephone,  telegram  or  other  means of
communication. Such directors, officers and  employees will not be  additionally
compensated  for, but may  be reimbursed for  out-of-pocket expenses incurred in
connection with,  such  solicitation.  Arrangements have  also  been  made  with
brokerage  firms, banks, custodians, nominees and fiduciaries for the forwarding
of proxy and solicitation material to owners of P-B Common Stock held of  record
by  such persons, and in connection therewith  such firms will be reimbursed for
reasonable expenses incurred in forwarding such materials. P-B and Nellcor  have
each retained Corporate Investor Communications, Inc. to aid in the solicitation
of  proxies from their respective stockholders.  The aggregate fees of such firm
for the solicitation  of proxies from  the stockholders of  P-B and Nellcor  are
estimated to be $15,000 plus reimbursement of out-of-pocket expenses.

QUORUM

    The  presence  in person  or  by properly  executed  proxy of  holders  of a
majority of  all  of the  issued  and outstanding  shares  of P-B  Common  Stock
entitled to vote is necessary to constitute a quorum at the P-B Special Meeting.

REQUIRED VOTE

    Adoption of the Merger Agreement requires the affirmative vote of a majority
of  the outstanding shares of  P-B Common Stock entitled  to vote thereon at the
P-B Special Meeting. For  purposes of determining  whether the Merger  Agreement
has been adopted, the inspectors of election will include abstentions and broker
non-votes  in the number of  outstanding shares of P-B  Common Stock entitled to
vote thereon at  the P-B  Special Meeting. Accordingly,  abstentions and  broker
non-votes  will have  the effect  of a "NO"  vote on  the proposal  to adopt the
Merger Agreement.

    As of  June 30,  1995, directors  and executive  officers of  P-B and  their
affiliates  were  beneficial owners  of an  aggregate of  179,276 shares  of P-B
Common Stock  (exclusive of  any  shares issuable  upon  the exercise  of  stock
options  remaining unexercised as  of such date), or  approximately 1.39% of the
12,922,092 shares of  P-B Common Stock  that were issued  and outstanding as  of
such  date. Each of the directors and executive officers of P-B has indicated an
intention to vote all shares  of P-B Common Stock  beneficially owned by him  or
her in favor of approval of the Merger Agreement.

    THE  MATTERS  TO BE  CONSIDERED  AT THE  P-B  SPECIAL MEETING  ARE  OF GREAT
IMPORTANCE TO THE STOCKHOLDERS  OF P-B. ACCORDINGLY,  STOCKHOLDERS ARE URGED  TO
READ   AND  CAREFULLY   CONSIDER  THE   INFORMATION  PRESENTED   IN  THIS  PROXY
STATEMENT/PROSPECTUS, AND  TO  COMPLETE,  DATE, SIGN  AND  PROMPTLY  RETURN  THE
ENCLOSED PROXY IN THE ENCLOSED POSTAGE-PAID ENVELOPE.

                                       19
<PAGE>
                                   THE MERGER

    THIS  SECTION OF THE PROXY STATEMENT/PROSPECTUS DESCRIBES CERTAIN ASPECTS OF
THE PROPOSED MERGER. TO THE EXTENT THAT  IT RELATES TO THE MERGER AGREEMENT  AND
THE  TERMS  OF THE  MERGER, THE  FOLLOWING  DESCRIPTION DOES  NOT PURPORT  TO BE
COMPLETE AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO THE MERGER  AGREEMENT,
INCLUDING  THE  AMENDMENT  THERETO,  WHICH  ARE ATTACHED  AS  ANNEXES  A  AND B,
RESPECTIVELY, TO THIS PROXY STATEMENT/PROSPECTUS AND ARE INCORPORATED HEREIN  BY
REFERENCE.  ALL STOCKHOLDERS ARE  URGED TO READ  THE MERGER AGREEMENT, INCLUDING
THE AMENDMENT THERETO, IN ITS ENTIRETY.

GENERAL

    The Merger Agreement  provides that the  Merger will be  consummated if  the
approvals of the Nellcor and P-B stockholders required therefor are obtained and
all  other conditions to the  Merger are satisfied or  waived as provided in the
Merger Agreement. Upon consummation of the  Merger, Sub will be merged with  and
into P-B, and P-B will become a wholly-owned subsidiary of Nellcor.

    Upon  consummation of the Merger, each outstanding share of P-B Common Stock
(other than  shares  held in  the  treasury of  P-B,  which will  be  canceled),
including the associated P-B Common Stock Purchase Right, will be converted into
the  right to receive  0.88 of a  fully paid and  nonassessable share of Nellcor
Common Stock, including  the corresponding percentage  of an associated  Nellcor
Preferred  Stock Purchase  Right. Cash will  be delivered in  lieu of fractional
shares as described in the Merger Agreement.

    Based upon the capitalization of  Nellcor and P-B as  of July 19, 1995,  the
stockholders  of P-B  will own  approximately 40.5%  of the  outstanding Nellcor
Common Stock  following  consummation of  the  Merger assuming  no  exercise  of
outstanding  options to acquire  Nellcor Common Stock or  P-B Common Stock. Such
percentage could  change depending  on  whether and  to  what extent  shares  of
Nellcor  Common Stock and P-B Common Stock issuable upon exercise of outstanding
Nellcor or P-B stock options are issued.

EFFECTIVE TIME

    The effective time of the Merger (the "Effective Time") will occur upon  the
filing  of a Certificate of  Merger with the Secretary of  State of the State of
Delaware (the "Certificate of Merger") or at such later time as is specified  on
such  certificate. The filing of the Certificate of Merger will occur as soon as
practicable after the  closing of  the transactions contemplated  by the  Merger
Agreement.  The Merger Agreement may be terminated by either party if the Merger
has not been consummated on or before December 31, 1995 and under certain  other
conditions.  See "The Merger Agreement --  Conditions" and "The Merger Agreement
- -- Termination."

CONVERSION OF SHARES; PROCEDURES FOR EXCHANGE OF CERTIFICATES

    The conversion of  P-B Common Stock  and related P-B  Common Stock  Purchase
Rights into the right to receive Nellcor Common Stock, related Nellcor Preferred
Stock  Purchase  Rights,  and  cash  in lieu  of  fractional  shares  will occur
automatically at the Effective Time.

    As soon as practicable after the  Effective Time, a transmittal letter  will
be  mailed  by the  Exchange Agent  to  each stockholder  of P-B  informing such
stockholder of the procedures to follow in forwarding P-B stock certificates  to
the  Exchange Agent.  Upon receipt of  the P-B stock  certificates, the Exchange
Agent will deliver whole shares of  Nellcor Common Stock to the stockholder  and
cash  in lieu of fractional shares pursuant to the terms of the Merger Agreement
and in accordance with  the transmittal letter, together  with any dividends  or
other distributions to which such stockholder may be entitled.

    If  any issuance of shares of Nellcor Common Stock in exchange for shares of
P-B Common Stock is  to be made to  a person other than  the P-B stockholder  in
whose  name the certificate  is registered at  the Effective Time,  it will be a
condition of  such exchange  that  the certificate  so surrendered  be  properly
endorsed  or  otherwise  be  in  proper  form  for  transfer  and  that  the P-B
stockholder requesting  such  issuance either  pay  any transfer  or  other  tax
required  or establish to the  satisfaction of the Exchange  Agent that such tax
has been paid or is not payable.

                                       20
<PAGE>
    After the Effective Time, there will  be no further transfers of P-B  Common
Stock  on the  stock transfer  books of P-B.  If a  certificate representing P-B
Common Stock is presented  for transfer, it will  be canceled and a  certificate
representing  the appropriate number of full  shares of Nellcor Common Stock and
cash in lieu of  fractional shares and any  dividends and distributions will  be
issued in exchange therefor.

    After  the Effective Time and until  surrendered, shares of P-B Common Stock
will be deemed for all corporate  purposes, other than the payment of  dividends
and distributions, to evidence ownership of the number of full shares of Nellcor
Common  Stock into which such  shares of P-B Common  Stock were converted at the
Effective Time. No dividends or other distributions, if any, payable to  holders
of  Nellcor Common  Stock will be  paid to  the holders of  any certificates for
shares of  P-B  Common  Stock  until such  certificates  are  surrendered.  Upon
surrender  of such certificates,  all such declared  dividends and distributions
which shall have  become payable with  respect to such  Nellcor Common Stock  in
respect  of a record date after the Effective Time will be paid to the holder of
record of the full shares of Nellcor Common Stock represented by the certificate
issued in exchange therefor, without interest.

    P-B STOCKHOLDERS SHOULD NOT FORWARD CERTIFICATES FOR P-B COMMON STOCK TO THE
EXCHANGE AGENT UNTIL  THEY HAVE RECEIVED  TRANSMITTAL LETTERS. P-B  STOCKHOLDERS
SHOULD NOT RETURN STOCK CERTIFICATES WITH THE ENCLOSED PROXY.

BACKGROUND OF THE MERGER

    Increased  competitive pressures in the health care industry and significant
health care reform initiatives have contributed to a trend towards consolidation
in the industry. Partially  in response to these  trends, Nellcor established  a
strategic  objective to grow through  acquisitions and strategic combinations in
order to broaden its product line  and enhance its competitive position. At  its
meeting on January 11, 1994, the Nellcor Board established a strategic objective
to  seek acquisitions and  merger candidates. As part  of this strategy, Nellcor
retained Robertson  Stephens in  May 1994  to identify  possible candidates  for
acquisition  by  or  strategic combination  with  Nellcor.  P-B was  one  of the
companies identified  by  Robertson  Stephens  as a  possible  candidate  for  a
strategic  business  combination  with  Nellcor.  Since  the  adoption  of  that
strategy, Nellcor has  initiated discussions  with a number  of other  potential
merger and acquisition candidates for a strategic business combination.

    In  the  Summer and  Fall of  1993, P-B  commenced consideration  of various
strategic alternatives available to  P-B as a means  to address the P-B  Board's
concern  with  the perceived  undervaluation of  P-B's stock  in the  market. In
December 1993, the P-B Board authorized the retention of Smith Barney to explore
the sale by P-B of its FOxS intra-arterial blood gas monitoring systems division
or the establishment of a strategic  alliance with respect to the FOxS  division
and  strategic alternatives,  including the possibility  of a  separation of the
hospital and home health care operations of P-B.

    During the period from May 1994  to September 1994, C. Raymond Larkin,  Jr.,
President   and   Chief  Executive   Officer   of  Nellcor,   initiated  several
conversations with Burton A. Dole, Jr., Chairman, President and Chief  Executive
Officer  of P-B, regarding  the possibility of a  strategic alliance or business
combination  between  Nellcor   and  P-B.  These   initial  conversations   were
preliminary in nature and primarily addressed the strategic reasons for pursuing
a business combination.

    During  July 1994,  Mr. Dole  had several  meetings with  representatives of
Thermo Electron Corp.  ("Thermo Electron"). During  these meetings, the  parties
addressed  the  possibility of  technology  sharing arrangements  between Thermo
Electron and  P-B and  the possible  sale by  P-B of  its blood  gas  monitoring
business or technology. Representatives of Thermo Electron also indicated to Mr.
Dole an interest in possibly acquiring P-B.

    At  the P-B Board meeting on August 31, 1994, Mr. Dole advised the P-B Board
of his conversations with Thermo Electron  and Thermo Electron's interest in  an
acquisition  of P-B. At the meeting, the P-B Board determined that it was not in
the best interest of P-B  and its stockholders to pursue  a sale of P-B at  that
time.

                                       21
<PAGE>
    On September 19, 1994, Mr. Dole had a telephone conversation with Dr. George
N.  Hatsopoulos, Chief  Executive Officer  and Chairman  of the  Board of Thermo
Electron, in which Dr. Hatsopoulos indicated that Thermo Electron had acquired a
4.9% interest  in P-B,  that Thermo  Electron was  definitely interested  in  an
acquisition of P-B and that it might be in the best interest of P-B to retain an
investment  banker to assist in evaluating  any offer that Thermo Electron might
wish to make.

    P-B retained Smith Barney  to act as its  financial advisor with respect  to
the proposal made by Thermo Electron and related matters. On September 22, 1994,
Dr. Hatsopoulos contacted Mr. Dole again to reiterate Thermo Electron's interest
in  an acquisition  of P-B  and to  suggest that  P-B's counsel  contact Seth H.
Hoogasian, General  Counsel of  Thermo Electron.  Over the  course of  the  next
several  days  there were  a number  of conversations  between Daniel  C. Weary,
General Counsel and a director of P-B, and Mr. Hoogasian, as well as between Mr.
Dole and Dr. Hatsopoulos.

    In September 1994, Mr.  Dole contacted Mr. Larkin  to request a meeting.  In
response to Mr. Dole's request, a meeting occurred on September 22, 1994 between
Mr.  Dole  and John  H.  Morrow, Executive  Vice  President and  Chief Operating
Officer of P-B, and Mr. Larkin  and Michael P. Downey, Executive Vice  President
and Chief Financial Officer of Nellcor. During the meeting the parties discussed
various  preliminary matters related to  a possible business combination between
Nellcor and P-B.

    A follow-up  meeting occurred  in  Denver, Colorado  on September  27,  1994
between  Mr. Dole and Mr. Larkin. On September 29, 1994, Mr. Dole telephoned Mr.
Larkin to advise  him that P-B  was not interested  in further discussions  with
Nellcor at that time.

    On  October 6, 1994,  Mr. Hoogasian of Thermo  Electron telephoned Mr. Weary
and informed him that Thermo Electron was sending a letter to Mr. Dole proposing
a merger transaction. Later that day P-B received a letter from Thermo  Electron
containing  an unsolicited proposal to acquire  all of the outstanding shares of
P-B for a price of $21 per share. On October 6, 1994, P-B announced the  receipt
of  the unsolicited  proposal from  Thermo Electron  and its  retention of Smith
Barney and Shearman & Sterling,  as financial and legal advisors,  respectively,
with respect to the Thermo Electron proposal.

    During  the  remainder of  1994, there  were a  number of  developments with
respect to  Thermo  Electron's  proposal  to acquire  P-B,  including:  (i)  the
announcement  by  the P-B  Board on  October 11,  1994 of  its rejection  of the
initial $21 per share acquisition proposal made by Thermo Electron; (ii)  Thermo
Electron's  second proposal on October  12, 1994 to acquire  P-B in a negotiated
merger transaction at a price of  $24 per share; (iii) Thermo Electron's  launch
on  October 24,  1994 of a  tender offer  to acquire all  outstanding P-B Common
Stock at a price of $24.50 per share; (iv) the announcement of the P-B Board  on
November  7, 1994 of its recommendation  that P-B stockholders reject the Thermo
Electron tender offer; and (v) the expiration on December 8, 1994 of the  Thermo
Electron tender offer.

    During  the  pendency  of  the Thermo  Electron  offer,  Nellcor's financial
advisors contacted P-B's  financial advisors on  several occasions to  reiterate
Nellcor's  interest in pursuing a strategic business combination between the two
companies. P-B's financial advisors indicated on  the occasion of each of  these
contacts  that P-B was not interested in  pursuing a transaction with Nellcor at
such time.

    On February 23, 1995, P-B's financial advisors contacted Nellcor's financial
advisors to suggest  resuming discussions  of a  strategic business  combination
between  the  two  companies.  Shortly  thereafter,  Nellcor  and  P-B  executed
confidentiality agreements.

    On March 7, 1995,  Mr. Dole and Mr.  Morrow (the "P-B Representatives")  met
with  Mr. Larkin, Mr. Downey and  Ms. Laureen DeBuono, Executive Vice President,
Human  Resources,  General  Counsel  and  Secretary  of  Nellcor  (the  "Nellcor
Representatives"),  to  discuss  a variety  of  issues relating  to  a strategic
combination between Nellcor and P-B. At this meeting, it was suggested that  Mr.
Larkin  attend the next meeting  of the P-B Board  in order to outline Nellcor's
views regarding a strategic combination between the two companies.

                                       22
<PAGE>
    During  March  1995,  Smith  Barney   and  Robertson  Stephens  engaged   in
preliminary  negotiations  concerning valuation  issues  regarding pricing  in a
stock-for-stock merger.

    On April 5, 1995, Mr. Larkin outlined to the P-B Board Nellcor's view of the
strategic reasons  for  a business  combination  between Nellcor  and  P-B.  Mr.
Downey, Ms. DeBuono and a representative of Robertson Stephens also attended the
P-B Board meeting.

    On  April 7, 1995,  the P-B Representatives  and the Nellcor Representatives
met in Salt Lake City, Utah to discuss composition of the Board of Directors  of
the  combined companies after a merger and other issues related to management of
the combined operations.

    On April 12, 1995, more  extensive due diligence discussions commenced  with
meetings  in Kansas City, Missouri and continued through the date of the signing
of the Merger Agreement. During  the remainder of April  and in the first  three
weeks  of May, representatives of Nellcor and P-B and their respective legal and
financial advisors held  a series  of discussions  concerning the  terms of  the
proposed business combination including negotiations of the Merger Agreement and
related  issues concerning  employee benefits  and employment  arrangements with
respect to Mr. Dole and Mr. Morrow.

    Final agreement on the terms of the Exchange Ratio was reached at a  meeting
involving Mr. Dole, P-B's financial advisors, Mr. Larkin and Nellcor's financial
advisors  on the  evening of  May 19,  1995. The  remaining terms  of the Merger
Agreement and the  related issues  concerning employee  benefits and  employment
arrangements  with  respect to  Mr. Dole  and Mr.  Morrow were  finalized during
negotiations on May 20, 1995.

    During this time period, the status  of negotiations regarding the terms  of
the  Merger  Agreement  and issues  concerning  valuation were  reported  to the
Nellcor Board in meetings held on April 24, April 30 and May 21, 1995 and to the
P-B Board in meetings on April 25, April 30 and May 21, 1995.

    In the conference call with the Nellcor Board on April 24, 1995, Mr. Larkin,
Mr. Downey  and  Ms.  DeBuono  reported  on the  status  of  the  due  diligence
investigation  of P-B  and the  negotiations with P-B  regarding the  terms of a
proposed business combination. The Nellcor Board authorized its management  team
and financial and legal advisors to continue negotiations with P-B and to pursue
further due diligence of P-B and its operations.

    During  the meeting of the Nellcor Board  on April 30, 1995, Mr. Larkin, Mr.
Downey and Ms.  DeBuono updated the  Nellcor Board regarding  the status of  the
proposed  transaction  and  Robertson  Stephens presented  its  analysis  of the
financial impact to  Nellcor and its  stockholders of the  Merger using  various
possible  exchange ratios. The Nellcor  Board reaffirmed its prior authorization
to pursue negotiation of  the transaction and gave  its management team  certain
parameters  concerning  valuation  and  other  issues  to  be  addressed  in the
negotiations.

    In the  meeting of  the P-B  Board held  on April  30, 1995,  the P-B  Board
discussed  with the P-B  Representatives and P-B's  legal and financial advisors
the status  of the  due diligence  investigation of  Nellcor, the  draft  Merger
Agreement and negotiations with respect to the Exchange Ratio.

    In  its meeting on May 21, 1995,  the Nellcor Board unanimously approved the
final terms of  the Merger  Agreement. Each  of Robertson  Stephens and  Goldman
Sachs provided to the Nellcor Board its and their analysis, respectively, of the
financial terms of the Merger. Robertson Stephens provided its oral opinion that
the  Exchange Ratio was fair  to Nellcor and its  stockholders, from a financial
point of view, and Goldman Sachs  provided their oral opinion that the  Exchange
Ratio was fair to Nellcor, in each case as of the date of such opinions.

    In its meeting on May 21, 1995, the P-B Board unanimously approved the final
terms  of  the Merger  Agreement. Smith  Barney  provided to  the P-B  Board its
analysis of the financial terms of the Merger and provided to the P-B Board  its
oral  opinion that  the Exchange  Ratio was  fair to  the holders  of P-B Common
Stock, from a financial point of view, as of the date of such opinion.

                                       23
<PAGE>
    As of June 30, 1995, the parties entered into Amendment No. 1 to the  Merger
Agreement  in order to allow additional time  for the selection of the third new
member to be added to the Nellcor Board in connection with the Merger.

RECOMMENDATION OF THE NELLCOR BOARD; REASONS FOR THE MERGER AND OTHER PROPOSALS

    THE  NELLCOR  BOARD  HAS  UNANIMOUSLY  APPROVED  THE  TERMS  OF  THE  MERGER
AGREEMENT,  BELIEVES THAT THE TERMS OF THE  MERGER AGREEMENT ARE FAIR TO, AND IN
THE BEST INTERESTS OF, NELLCOR AND ITS STOCKHOLDERS, AND UNANIMOUSLY  RECOMMENDS
THAT  HOLDERS  OF SHARES  OF NELLCOR  COMMON  STOCK VOTE  "FOR" APPROVAL  OF THE
NELLCOR SHARE PROPOSAL, THE  NELLCOR CHARTER AMENDMENT  PROPOSAL, THE 1995  PLAN
PROPOSAL AND THE 1994 PLAN AMENDMENT PROPOSAL.

    The  Nellcor Board has concluded  that the terms of  the proposed Merger are
fair to, and in the best interests of, Nellcor and its stockholders. The Nellcor
Board also has concluded that  the proposed Merger is  in the best interests  of
Nellcor  and its  stockholders because,  among other  reasons, the  Merger would
further Nellcor's strategic objectives of enhancing its competitive position  in
the  rapidly consolidating  health care  industry, primarily  via growth through
acquisition, expanding its  existing product line  to include complementary  new
products  and  obtaining manufacturing  and other  synergies, and  would enhance
Nellcor's product  offerings to  respiratory  impaired patients  throughout  the
continuum of care.

    The  Nellcor  Board concluded  that the  proposed  Merger will  further such
strategic objectives because of its belief that: (i) the larger size and broader
product offering of  the combined  companies will  enable them  to respond  more
fully  to the  demands of the  rapidly consolidating health  care industry; (ii)
P-B's product line complements that of Nellcor and enhances the market  presence
of  both companies in  the respiratory products industry;  (iii) Nellcor and P-B
may be able  to realize manufacturing,  marketing and distribution  efficiencies
through greater economies of scale and the elimination of redundancies; and (iv)
Nellcor  and P-B may  be able to  realize increased product  innovation from the
combination of their respective research and development activities.

    In reaching its conclusion that the proposed  Merger is fair to, and in  the
best  interests  of,  Nellcor  and  its  stockholders,  the  Nellcor  Board also
considered, among other factors, (i) its knowledge of the business,  operations,
properties,  assets,  financial condition,  operating  results and  prospects of
Nellcor and P-B; (ii)  current industry, economic  and market conditions;  (iii)
presentations  by Nellcor's management with respect to, and the analysis of each
of Robertson Stephens and  Goldman Sachs of, Nellcor,  P-B and the Merger;  (iv)
the  opinion of Robertson Stephens that, as  of May 21, 1995, the Exchange Ratio
was fair to Nellcor and  its stockholders, from a  financial point of view,  and
the  opinion of Goldman Sachs, dated May 21, 1995, to the effect that, as of the
date of such opinion,  the Exchange Ratio pursuant  to the Merger Agreement  was
fair to Nellcor (see "-- Opinions of Robertson Stephens and Goldman Sachs"); (v)
the  terms  of  the Merger  Agreement  (see  "The Merger  Agreement");  (vi) the
accounting and  tax treatment  of  the Merger;  and  (vii) the  opportunity  for
Nellcor stockholders to participate in a larger, more diversified company.

    In  view  of  the  variety  of factors  considered  in  connection  with its
evaluation of the Merger, the Nellcor Board  did not find it practicable to  and
did  not quantify or  otherwise assign relative weights  to the specific factors
considered in reaching its determination. In addition, individual members of the
Nellcor Board may have given different weights to different factors.

RECOMMENDATION OF THE P-B BOARD; REASONS FOR THE MERGER

    THE P-B BOARD HAS  UNANIMOUSLY APPROVED THE TERMS  OF THE MERGER  AGREEMENT,
BELIEVES  THAT THE TERMS  OF THE MERGER AGREEMENT  ARE FAIR TO,  AND IN THE BEST
INTERESTS OF, P-B AND ITS STOCKHOLDERS, AND UNANIMOUSLY RECOMMENDS THAT  HOLDERS
OF SHARES OF P-B COMMON STOCK VOTE "FOR" APPROVAL OF THE MERGER AGREEMENT.

                                       24
<PAGE>
    In  reaching its  decision to  approve the  Merger Agreement,  the P-B Board
considered the  following factors:  (i) information  relating to  the  business,
assets,  management,  competitive position  and  prospects of  P-B  and Nellcor,
including the prospects of P-B if it were to continue as an independent company;
(ii) the financial condition,  cash flows and results  of operations of P-B  and
Nellcor,  both on an historical and on a prospective basis; (iii) the historical
trading price for the P-B  Common Stock and the  Nellcor Common Stock; (iv)  the
percentage   of  equity  in  the  combined  companies  to  be  received  by  P-B
stockholders in relation to the relative  contribution of Nellcor and P-B  based
on,  among other things, revenues, earnings before interest, taxes, depreciation
and amortization  ("EBITDA"),  net  income  and book  value;  (v)  the  enhanced
position  of the combined companies to  compete more effectively in the changing
health care environment and the  ongoing consolidation of health care  providers
and  payors;  (vi)  the potential  efficiencies,  eliminations  of redundancies,
economies of scale and other synergies that  may be realized as a result of  the
combination  of  P-B's  and  Nellcor's operations;  (vii)  the  increased market
capitalization and  financial strength  of the  combined companies;  (viii)  the
opportunity  for P-B stockholders to receive a premium over the market price for
their shares immediately prior to the  announcement of the Merger (the  Exchange
Ratio represented a premium of approximately 39% over the closing sales price of
$26.125  per share  of P-B Common  Stock on May  19, 1995, the  last trading day
prior to the announcement of the Merger, based upon 0.88 times the closing sales
price per  share  of Nellcor  Common  Stock ($41.25)  on  such date);  (ix)  the
structure  of the Merger, which will permit  holders of P-B Common Stock to have
all of their shares converted into Nellcor Common Stock on a tax-free basis; and
(x) the financial presentation and opinion  of Smith Barney as to the  fairness,
from  a financial  point of view,  of the Exchange  Ratio to the  holders of P-B
Common Stock (see "-- Opinion of Smith Barney").

    The recommendation  of  the  P-B  Board also  took  into  consideration  the
proposed  inclusion on  the Nellcor  Board after  the Merger  of representatives
familiar with P-B's businesses  and operations and the  P-B Board's belief  that
the  interests of P-B's  employees, customers, suppliers  and the communities in
which P-B has operated will be well  served by the combined companies after  the
consummation of the Merger.

    In  view  of  the  variety  of factors  considered  in  connection  with its
evaluation of the Merger, the P-B Board did not find it practicable to, and  did
not,  quantify or  otherwise assign  relative weights  to the  specified factors
considered in reaching  this determination. In  addition, individual members  of
the P-B Board may have given different weights to different factors.

OPINIONS OF ROBERTSON STEPHENS AND GOLDMAN SACHS

    OPINION  OF ROBERTSON STEPHENS.  Nellcor  retained Robertson Stephens to act
as its financial advisor in connection  with the Merger. Robertson Stephens  was
retained  based  on Robertson  Stephens' experience  as  a financial  advisor in
connection with mergers and acquisitions as well as Robertson Stephens' industry
knowledge and familiarity with Nellcor.

    At the May 21, 1995 special meeting of the Nellcor Board, Robertson Stephens
delivered its opinion  to the  effect that,  as of such  date and  based on  the
matters  described  therein, the  Exchange  Ratio was  fair  to Nellcor  and its
stockholders from  a  financial  point  of  view.  Robertson  Stephens  did  not
recommend  to  Nellcor  that  any  specific  ratio  constituted  the appropriate
exchange ratio for the Merger. Robertson Stephens' opinion to the Nellcor  Board
addresses  only the  fairness to Nellcor  and its stockholders  from a financial
point of view of the Exchange Ratio, and does not constitute a recommendation to
any stockholder as to  how such stockholder should  vote at the Nellcor  Special
Meeting.

    THE  COMPLETE TEXT OF THE  OPINION DATED MAY 21,  1995 IS ATTACHED HERETO AS
ANNEX C AND  THE SUMMARY  OF THE  OPINION SET FORTH  BELOW IS  QUALIFIED IN  ITS
ENTIRETY  BY REFERENCE TO THE FULL TEXT OF SUCH OPINION. STOCKHOLDERS OF NELLCOR
ARE URGED TO READ SUCH OPINION CAREFULLY  AND IN ITS ENTIRETY FOR A  DESCRIPTION
OF  THE PROCEDURES  FOLLOWED, THE FACTORS  CONSIDERED, THE  ASSUMPTIONS MADE AND
SCOPE OF  THE  REVIEW  UNDERTAKEN BY,  AS  WELL  AS LIMITATIONS  ON  THE  REVIEW
UNDERTAKEN BY, ROBERTSON STEPHENS IN RENDERING ITS OPINION.

                                       25
<PAGE>
    In  connection  with the  preparation  of its  opinion  dated May  21, 1995,
Robertson Stephens  among  other  things:  (i)  reviewed  financial  information
relating to Nellcor and P-B furnished to it by both companies, including certain
internal financial analyses and forecasts prepared by Nellcor's management; (ii)
reviewed  publicly  available  information;  (iii)  held  discussions  with  the
managements of  Nellcor  and  P-B  concerning the  business,  past  and  current
business operations, results of regulatory examinations, financial condition and
future  prospects  of  both  companies,  independently  and  combined, including
certain information  prepared jointly  by  the managements  of Nellcor  and  P-B
concerning  potential  cost savings  and synergies  that  could result  from the
Merger; (iv) reviewed  the Merger Agreement;  (v) reviewed the  stock price  and
trading  histories of  both companies;  (vi) reviewed  the contribution  by each
company to pro forma  combined revenue, gross  income, research and  development
expenditures, operating income, pretax income and net income; (vii) reviewed the
valuations  of publicly traded  companies which it  deemed comparable to Nellcor
and  P-B;  (viii)  compared  the  financial  terms  of  the  Merger  with  other
transactions  which  it  deemed  relevant; (ix)  prepared  discounted  cash flow
analyses of both companies; (x) analyzed the pro forma earnings per share of the
combined company; and (xi) made such other studies and inquiries, reviewed  such
other data, as it deemed relevant.

    Based  on past  activities, Robertson Stephens  has a  substantial degree of
familiarity with  Nellcor.  In  addition,  in  the  course  of  its  engagement,
Robertson  Stephens completed further investigation of  both Nellcor and P-B. In
arriving at  its  opinion, however,  Robertson  Stephens did  not  independently
verify  any of the foregoing information and  has relied on all such information
being complete and  accurate in  all material  respects. Furthermore,  Robertson
Stephens  did not obtain  any independent appraisal of  the properties or assets
and liabilities of Nellcor or P-B or of any of their subsidiaries. With  respect
to  the  financial  and  operating  forecasts  (and  the  assumptions  and bases
therefor) of  Nellcor  and  P-B which  Robertson  Stephens  reviewed,  Robertson
Stephens  assumed that such forecasts have  been reasonably prepared and reflect
the best available estimates  and judgments of  such respective managements  and
that  such projections and forecasts will be  realized in the amounts and in the
time periods  currently estimated  by the  managements of  Nellcor and  P-B.  In
addition,  Robertson Stephens has relied upon estimates and judgments of Nellcor
and P-B managements as  to the future financial  performance of both  companies,
including  the cost savings  and synergies resulting  from the Merger. Robertson
Stephens also assumed  that the Merger  will be  accounted for as  a pooling  of
interests  under  generally  accepted  accounting  principles.  While  Robertson
Stephens believes that its review, as described within, is an adequate basis for
the opinion that Robertson Stephens expresses, this opinion is necessarily based
upon market, economic, and other conditions  that exist and can be evaluated  as
of  the date of the opinion, and  on information available to Robertson Stephens
as of such date.

    The following  paragraphs summarize  the most  significant quantitative  and
qualitative  analyses performed by Robertson Stephens in arriving at its opinion
and reviewed  by  the Nellcor  Board  and does  not  purport to  be  a  complete
description  of the  analyses performed  by Robertson  Stephens. The information
presented below is based on the financial  condition of Nellcor and P-B as of  a
date  or dates shortly before the Merger  Agreement was executed on May 21, 1995
and stock price information through the close of the market on May 19, 1995.

    STOCK PRICE AND TRADING  HISTORY.  Robertson  Stephens reviewed the  trading
activity  including price  and volume  of P-B and  Nellcor for  the one-year and
five-year periods since May 19, 1994 and May 18, 1990 respectively. With respect
to P-B, Robertson  Stephens noted that,  since May 18,  1990, the daily  closing
prices of the P-B Common Stock ranged from a high of $36.00 on November 20, 1992
to  a low of  $13.25 on September  28, 1990. With  respect to Nellcor, Robertson
Stephens noted that, since May 18, 1990, the daily closing prices of the Nellcor
Common Stock ranged from a high of $45.25 on  May 2, 1995 to a low of $8.625  on
November  11,  1990.  In  addition,  Robertson  Stephens  compared  the  indexed
performance of Nellcor Common  Stock, P-B Common  Stock, Datascope Corp.  Common
Stock,  Healthdyne Technologies, Inc. Common  Stock, Marquette Electronics, Inc.
Common Stock,  Protocol Systems,  Inc. Common  Stock, Respironics,  Inc.  Common
Stock, and Spacelabs Medical, Inc.

                                       26
<PAGE>
Common  Stock since May  19, 1994. Robertson Stephens  also compared the indexed
performance of Nellcor Common Stock, P-B Common Stock, the Standard & Poor's 500
Index, the  Robertson Stephens  Medical Products/Supplies  Index, the  Robertson
Stephens Health Care Index and the Comparable Companies Index, consisting of the
aforementioned  companies,  since  November  3,  1994.  In  addition,  Robertson
Stephens reviewed selected commentary of  research analysts at different  points
in the trading histories of Nellcor Common Stock and P-B Common Stock.

    EXCHANGE  RATIO ANALYSIS.  Robertson Stephens reviewed the exchange ratio of
shares of Nellcor  Common Stock per  share of  P-B Common Stock  implied by  the
daily  closing  prices of  P-B  and Nellcor  Common  Stock since  May  19, 1994.
Robertson Stephens noted that the average  implied exchange ratio since May  19,
1994  was 0.664 with a high  of 0.901 on October 28, 1994  and a low of 0.515 on
April 24, 1995.

    Robertson Stephens reviewed  the premium represented  by the Exchange  Ratio
compared  to the implied exchange  ratios based on closing  prices as of one day
and four  weeks prior  to May  21, 1995.  Such premiums  were 38.9%  and  63.6%,
respectively.  In addition, Robertson Stephens  reviewed the premium represented
by the  Exchange Ratio  compared to  implied exchange  ratios based  on  average
historical  closing prices for the latest 10, 20 and 30 trading days, the latest
3, 6, and 9 months  and since May 19, 1994.  Such premiums ranged between  32.4%
and 49.6%.

    Robertson  Stephens compared price per share to projected fiscal year ending
July 1996 and  1997 earnings  per share ratios  for Nellcor  and P-B.  Robertson
Stephens  noted that Nellcor trades at a  higher price per share to earnings per
share ratio than  P-B. Robertson  Stephens also noted  that, in  the absence  of
synergies,  the exchange ratio that would be non-dilutive to the earnings of the
pro forma company for the  fiscal years ending July 1996  and 1997 is below  the
Exchange Ratio.

    CONTRIBUTION  ANALYSIS.   Robertson  Stephens  compared the  contribution of
Nellcor and  P-B to  pro  forma combined  revenue,  gross income,  research  and
development  expenditures, operating income, pre-tax  income, and net income for
calendar 1996, 1995, 1994 and the  last twelve months. Robertson Stephens  noted
that   P-B  contributes  approximately  54.4%-57.7%  of  revenue,  approximately
46.7%-48.4%  of  gross  income,   approximately  39.7%-44.1%  of  research   and
development   expenditures,  approximately  34.1%-39.1%   of  operating  income,
approximately 28.4%-32.8% of  pre-tax income, and  approximately 35.0%-40.1%  of
net   income.  Robertson  Stephens  compared   these  historical  and  projected
contribution figures with  the approximately 40.6%  ownership position that  P-B
stockholders  would  have in  the  pro forma  company  on a  fully-diluted basis
(treasury method).

    COMPARABLE COMPANY ANALYSIS.  Robertson Stephens compared certain  financial
data  and  multiples  of income  parameters  accorded to  other  publicly traded
companies deemed by Robertson Stephens to  be comparable to P-B. Financial  data
compared  included market capitalization,  total capitalization, revenues, gross
income,  operating  income,  net  income,  earnings  per  share,  gross  margin,
operating expenses as a percentage of revenues, operating margin, net margin and
projected  earnings  per  share  growth rate  as  reported  by  ZACKS. Multiples
compared included  total  capitalization  to revenue,  total  capitalization  to
operating  income, price per share to earnings  per share and price per share to
earnings per  share  divided  by  projected growth  rate.  Companies  deemed  by
Robertson  Stephens to be comparable to P-B included Datascope Corp., Healthdyne
Technologies, Inc.,  Marquette  Electronics, Inc.,  Nellcor,  Protocol  Systems,
Inc.,  Respironics,  Inc.,  SpaceLabs Medical,  Inc.,  Invacare  Corporation and
Sunrise Medical Inc. (the "Comparable Companies").

    For P-B, based on total capitalization to revenues multiples of 0.9-2.7  for
calendar  1994, 0.9-2.5 for the latest  twelve months, and 0.8-2.1 for projected
calendar 1995  for the  Comparable  Companies, implied  equity value  per  share
ranged  from $15.76 to $61.94. Based on total capitalization to operating income
multiples of 7.5-18.5 for calendar 1994, 7.6-17.7 for the latest twelve  months,
and  6.5-11.9 for  projected calendar 1995  for the  Comparable Companies, P-B's
implied equity value per share ranged from  $7.58 to $31.45. Based on price  per
share  to earnings per share multiples of 13.8-26.8 for calendar 1994, 13.8-26.8
for the  latest  twelve  months,  12.6-18.7  for  projected  calendar  1995  and
11.0-15.2  for  projected  calendar  1996 for  the  Comparable  Companies, P-B's
implied equity value per share ranged

                                       27
<PAGE>
from $17.73 to  $40.36. Based on  the average  price per share  to earnings  per
share  divided by projected  growth rate multiple of  0.8-1.4 for calendar 1995,
P-B's implied equity value per share was $31.22 to $50.49.

    The average implied exchange ratio at the current Nellcor price per share of
$41.25 as of May 19, 1995, ranged  from 0.386 to 0.902. Robertson Stephens  also
noted that the Exchange Ratio was within this range.

    COMPARABLE  TRANSACTION ANALYSIS.  Robertson Stephens also analyzed publicly
available information  for 22  selected pending  or completed  acquisitions  and
mergers  within the medical device and medical equipment industries. The mergers
- -- listed with target(parent)/acquiror(parent)  (year of announcement) --  were:
Mitek  Surgical Products Inc./Johnson &  Johnson (1995); IVAC Corporation/ River
Medical  Incorporated  (1994);  SCIMED  Life  Systems,  Inc./Boston   Scientific
Corporation  (1994); NAMIC  USA Corporation/Pfizer Inc.  (1994); Laser Precision
Corporation/GN  Great  Nordic  Ltd.  (1994);  Cardiovascular  Imaging   Systems,
Inc./Boston  Scientific Corporation  (1994); Kinetic  Concepts, Inc.  -- certain
assets/Mediq  Incorporated  (1994);  Physio-Control  Corporation/Bain   Capital,
Incorporated   (1994);  Diasonics  Ultrasound  Incorporated/Elbit  Ltd.  (1994);
Corometrics Medical  Systems/  Marquette Electronics,  Inc.  (1994);  Interspec,
Inc./Advanced  Technology Laboratories, Inc. (1994); McGaw Inc./Ivax Corporation
(1994); Electromedics, Inc./MedTronic,  Inc. (1993); SEFAM  S.A./Puritan-Bennett
Corporation  (1993); DAR SpA/Mallinkrodt (Imcera  Group, Inc.) (1993), DeVilbiss
Health  Care  (Homecare  Holdings,  Inc.)/Sunrise  Medical  Inc.  (1993);   Wilj
International  Ltd.  (Wilj International  Holdings Ltd.)/investor  group (1992);
Abbott Laboratories  --  renal  dialysis division/Fresenius  USA,  Inc.  (1992);
Malvern  Instruments, Ltd. (Cray Electronics Holdings PLC)/Burnfield PLC (1992);
Patlex Corporation/AutoFinance  Group,  Inc.  (1992);  SpaceLabs  Medical,  Inc.
(Westmark  International,  Inc.)/shareholders  (1992);  and  Albion  Instruments
Inc./BOC Group PLC (1990). In  examining these transactions, Robertson  Stephens
analyzed  the premium paid over market price one  day and one month prior to the
announcement. Based on the premium to the price one day prior to announcement of
23.8%-78.7%, P-B's implied equity value per share ranged from $31.10 to  $44.89.
Based on the average premium to the price one month prior to the announcement of
34.4%-71.9%, P-B's implied equity value per share ranged from $29.24 to $37.40.

    In  addition,  Robertson  Stephens  reviewed  eight  recent  acquisitions or
mergers within the  medical device  and medical  equipment industries  involving
large   comparable  medical   equipment  companies.   The  mergers   were:  IVAC
Corporation/River   Medical    Incorporated   (1994);    Diasonics    Ultrasound
Incorporated/Elbit    Ltd.   (1994);   Corometrics   Medical   Systems/Marquette
Electronics, Inc. (1994); Interspec, Inc./Advanced Technology Laboratories, Inc.
(1994); McGaw Inc./Ivax Corporation (1994); Electromedics, Inc./MedTronic,  Inc.
(1993);  DeVilbiss  Health Care  (Homecare  Holdings Inc.)/Sunrise  Medical Inc.
(1993); and SpaceLabs Medical, Inc. (Westmark International,  Inc.)/shareholders
(1992).  In examining  these transactions,  Robertson Stephens  analyzed certain
financial parameters  of  the acquired  company  relative to  the  consideration
offered. Multiples analyzed included consideration offered plus net debt assumed
to  latest twelve months revenue, consideration offered plus net debt assumed to
latest  twelve  months   earnings  before   interest  and   income  taxes,   and
consideration  offered to latest twelve months net income. For P-B, based on the
consideration offered plus net debt to latest twelve months revenue multiples of
0.4-2.7, P-B's implied equity value per share ranged from $3.20 to $64.75; based
on the  "stripped"  multiples  (i.e.,  excluding  the  lowest  and  the  highest
multiples) of 0.77-1.66, P-B's implied equity value per share ranged from $13.79
to  $36.87. Based on the  average consideration offered plus  net debt to latest
twelve months earnings before interest  and income taxes multiple of  11.8-24.3,
P-B's  implied equity value per share ranged from $19.02 to $45.85. Based on the
average consideration offered  to latest  twelve months net  income multiple  of
19.2-33.3,  P-B's implied equity  value per share ranged  from $28.92 to $50.03.
Robertson Stephens also analyzed the premium paid over market price one day  and
one  month prior to the announcement. Based on  the premium to the price one day
prior to  announcement of  38.0%-78.7%,  P-B's implied  equity value  per  share
ranged  from $34.67 to $44.89. Based on the premium to the price one month prior
to announcement of 52.0%-66.7%, P-B's implied equity value per share ranged from
$33.07 to $36.27.

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<PAGE>
    The average implied exchange ratio at the current Nellcor price per share of
$41.25 as of May 19, 1995, ranged  from 0.643 to 0.935. Robertson Stephens  also
noted that the Exchange Ratio was within this range.

    DISCOUNTED CASH FLOW ANALYSIS.  Robertson Stephens also performed discounted
cash flow analyses of P-B and presented a range of average implied equity values
per P-B share of $23.70 to $45.81 with an average value of $33.56. In performing
these  analyses, Robertson Stephens selected  the following parameters: terminal
valuations between 10 times and 14 times latest twelve month operating income at
the end of fiscal year ending January 2001 and discount rates of between 11% and
19%.

    The implied exchange ratio at the current Nellcor price per share of  $41.25
as  of May 19, 1995,  ranged from 0.574 to  1.111. Robertson Stephens also noted
that the Exchange Ratio was within this range.

    In addition, Robertson Stephens also noted that the aforementioned valuation
analyses were based on P-B  as a stand-alone entity and  did not include any  of
the potential cost savings or synergies that could result from this merger.

    VALUATION  OF NELLCOR.   Robertson Stephens compared  certain financial data
and multiples of income statement  parameters accorded to other publicly  traded
medical  instrumentation companies deemed by Robertson Stephens to be comparable
to Nellcor.  Financial  data  compared  included  market  capitalization,  total
capitalization,  revenues, gross income, operating  income, net income, earnings
per share,  gross  margin,  operating  expenses as  a  percentage  of  revenues,
operating  margin,  net  margin, projected  earnings  per share  growth  rate as
reported by ZACKS. Multiples compared included total capitalization to  revenue,
total  capitalization to operating income, price per share to earnings per share
and price per  share to  earnings per share  divided by  projected growth  rate.
Companies  deemed by  Robertson Stephens  to be  comparable to  Nellcor included
Datascope Corp.,  Healthdyne Technologies,  Inc., Marquette  Electronics,  Inc.,
Protocol Systems, Inc., Respironics, Inc. and SpaceLabs Medical, Inc.

    Robertson  Stephens also performed discounted cash flow analyses of Nellcor.
In  performing  these  analyses,  Robertson  Stephens  selected  the   following
parameters:  terminal valuations  between 10  times and  14 times  latest twelve
month operating income at the end of  fiscal year ending June 2000 and  discount
rates of between 13.0% and 21.0%.

    Based  on  the multiples  compared and  the  discounted cash  flow analysis,
Nellcor's implied equity value per share ranged from $20.17 to $62.66.

    PRO FORMA MERGER ANALYSIS.  Robertson  Stephens also analyzed the pro  forma
earnings  per share of the combined companies  based on the Exchange Ratio. Such
analysis indicated  that,  in the  absence  of synergies  and  excluding  merger
related  expenses,  pro  forma earnings  per  share of  the  combined companies,
compared to Nellcor as a  stand-alone entity would be  reduced by 4.5% and  6.6%
for the fiscal years ending July 1996 and 1997, respectively.

    The  preparation of fairness opinions  involves various determinations as to
the most  appropriate  and  relevant quantitative  and  qualitative  methods  of
financial  analyses  and  the application  of  those methods  to  the particular
circumstances and,  therefore,  such opinions  are  not readily  susceptible  to
summary  description. Accordingly, Robertson Stephens believes its analyses must
be considered as a whole and that  considering any portion of such analyses  and
the  factors, without considering  all such analyses  and current factors, could
create a misleading or incomplete view of the process underlying such  opinions.
In  its analyses, Robertson  Stephens made numerous  assumptions with respect to
industry performance, general business and other conditions and matters, many of
which are beyond  the control  of Nellcor and  P-B. Any  estimates contained  in
these  analyses are not necessarily indicative of actual values or predictive of
future results or values, which may be significantly more or less favorable than
as set forth therein. In addition, analyses relating to the value of a  business
do  not purport to  be appraisals or  to reflect the  prices at which businesses
actually may be sold.

    Robertson Stephens was retained based  on Robertson Stephens' experience  as
financial  advisor  in  connection  with mergers  and  acquisitions  as  well as
Robertson Stephens' investment banking

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<PAGE>
relationship and  familiarity  with  Nellcor. Robertson  Stephens  has  provided
financial  advisory  and  investment  banking services  to  Nellcor  since 1987.
Robertson Stephens  acted as  underwriter  for the  initial public  offering  of
Nellcor in May 1987 and with respect to that transaction, Robertson Stephens has
been  compensated  for  such  services in  the  form  of  customary underwriting
discounts. Robertson Stephens also  makes a market in  Nellcor Common Stock.  In
the  course of its  market making and other  activities, Robertson Stephens may,
from time to time, have a long or short position in and buy and sell  securities
of Nellcor.

    Nellcor  formally engaged Robertson Stephens on May  24, 1994 by means of an
engagement letter  to provide  financial advisory  services in  connection  with
potential  merger or  acquisition transactions.  The engagement  letter provides
that, for its services,  Robertson Stephens is to  be paid, contingent upon  the
closing of the Merger, a fee of 1% of the total consideration to be paid to P-B,
as  defined  by such  letter.  Nellcor has  also  agreed to  reimburse Robertson
Stephens for its  reasonable out-of-pocket expenses  and to indemnify  Robertson
Stephens for certain liabilities relating to or arising out of services provided
by Robertson Stephens as financial advisor to Nellcor.

    Robertson   Stephens'  transaction   fee  is   currently  estimated   to  be
approximately $6.4 million based upon an estimated average stock price of $48.00
per share of  Nellcor Common  Stock, the number  of P-B's  fully diluted  shares
outstanding  (treasury method) as of June 30, 1995 and P-B's outstanding debt as
of June 30, 1995. The actual fees could be higher or lower, based upon Nellcor's
stock price, the number  of fully diluted  shares outstanding (treasury  method)
and the amount of outstanding debt immediately prior to the Merger.

    Robertson  Stephens is a  nationally recognized investment  banking firm. As
part of its investment banking business Robertson Stephens is frequently engaged
in the valuation of businesses and  their securities in connection with  mergers
and   acquisitions,   negotiated  underwritings,   secondary   distributions  of
securities, private placements and other purposes.

    OPINION OF GOLDMAN SACHS.  Goldman Sachs have delivered their opinion, dated
May 21, 1995, to the Nellcor  Board to the effect that,  as of the date of  such
opinion,  the  Exchange  Ratio pursuant  to  the  Merger Agreement  was  fair to
Nellcor.

    THE FULL TEXT OF THE WRITTEN OPINION  OF GOLDMAN SACHS, DATED MAY 21,  1995,
WHICH  SETS FORTH  ASSUMPTIONS MADE, MATTERS  CONSIDERED AND  LIMITATIONS ON THE
REVIEW UNDERTAKEN IN CONNECTION WITH THE OPINION, IS ATTACHED AS ANNEX D TO THIS
PROXY STATEMENT/PROSPECTUS AND IS INCORPORATED HEREIN BY REFERENCE. STOCKHOLDERS
OF NELLCOR ARE URGED TO, AND SHOULD, READ SUCH OPINION IN ITS ENTIRETY.

    In connection  with  their  opinion, Goldman  Sachs  reviewed,  among  other
things,  the Merger Agreement; Annual Reports to Stockholders and Annual Reports
on Form 10-K of  Nellcor for the  five fiscal years ended  July 3, 1994;  Annual
Reports  to Stockholders  and Annual  Reports on  Form 10-K  of P-B  for the two
fiscal years ended December  31, 1991 and the  three fiscal years ended  January
31,  1995; certain interim reports to stockholders and Quarterly Reports on Form
10-Q of Nellcor and P-B and certain other communications from Nellcor and P-B to
their respective stockholders; certain internal financial analyses and forecasts
for Nellcor  and P-B  prepared by  Nellcor management;  and certain  information
prepared jointly by the managements of Nellcor and P-B concerning potential cost
savings and synergies that could result from the Merger. Goldman Sachs also held
discussions  with members of the senior  management of Nellcor and P-B regarding
the past and  current business operations,  results of regulatory  examinations,
financial  condition  and future  prospects  of their  respective  companies. In
addition, Goldman Sachs  reviewed the  reported price and  trading activity  for
Nellcor  Common Stock and P-B Common Stock, compared certain financial and stock
market information  for Nellcor  and P-B  with similar  information for  certain
other  companies  the  securities of  which  are publicly  traded,  reviewed the
financial terms of certain  recent business combinations  in the medical  device
industry specifically and in other industries generally and performed such other
studies and analyses as they considered appropriate.

    Goldman  Sachs relied without independent verification upon the accuracy and
completeness of all of the financial and other information reviewed by them  for
purposes of this opinion. Goldman Sachs

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<PAGE>
also  relied  upon  the  management  of Nellcor  as  to  the  reasonableness and
achievability of the financial and operating forecasts (and the assumptions  and
bases  therefor) provided to them, and  with Nellcor's consent assumed that such
projections and forecasts  reflect the  best currently  available estimates  and
judgments  of the management of Nellcor  and that such projections and forecasts
will be realized in the amounts and  in the time periods currently estimated  by
the   management  of  Nellcor.  Furthermore,   Goldman  Sachs  relied  upon  the
managements of Nellcor and P-B as to the reasonableness and achievability of the
cost savings and synergies  resulting from the Merger,  as reflected in  certain
information (the "Synergies Information") prepared jointly by the managements of
Nellcor  and P-B (and the assumptions and  bases therefor) and provided to them,
and with Nellcor's  consent Goldman  Sachs assumed  that such  cost savings  and
synergies reflected the best currently available estimates and judgments of such
respective managements and that such cost savings and synergies will be realized
in the amounts and in the time periods currently estimated by the managements of
Nellcor  and  P-B.  In addition,  Goldman  Sachs  have not  made  an independent
evaluation or appraisal of the  assets and liabilities of  Nellcor or P-B or  of
any  of their respective subsidiaries and have  not been furnished with any such
evaluation or appraisal.  Goldman Sachs  also assumed,  with Nellcor's  consent,
that  the Merger  will be  recorded as  a pooling  of interests  under generally
accepted accounting principles.

    The following is  a summary  of certain of  the financial  analyses used  by
Goldman Sachs in connection with providing their opinion, dated May 21, 1995, to
the Nellcor Board, which opinion is attached hereto as Annex D.

        (i)   HISTORICAL  STOCK TRADING  ANALYSIS.   Goldman Sachs  reviewed the
    historical public trading prices  and volumes for  the Nellcor Common  Stock
    and  the P-B Common Stock (x) separately, on a daily basis from May 17, 1994
    to May 17, 1995 and on a weekly basis from May 12, 1992 to May 12, 1995, and
    (y) in comparison to selected companies in the medical device industry  (the
    "Medical  Device Composite"), on a daily basis  from May 17, 1994 to May 17,
    1995 and on a weekly basis from May 12, 1992 to May 12, 1995. Goldman  Sachs
    also  reviewed the  historical ratio  of the market  price per  share of P-B
    Common Stock to  the market price  per share  of Nellcor Common  Stock on  a
    weekly  basis from March 30,  1990 to May 12, 1995  and based on the average
    market prices  of  P-B  Common  Stock and  Nellcor  Common  Stock  over  the
    one-year,  6 month, 90 day, 60 day  and 30 day periods immediately preceding
    May 18, 1995. Such analysis indicated that the historic average ratio of the
    market price per share of P-B Common Stock to the market price per share  of
    Nellcor Common Stock ranged from 0.66 for the one year immediately preceding
    May 18, 1995 to 0.57 for the thirty days immediately preceding May 18, 1995,
    as compared to the Exchange Ratio of 0.88 of a share of Nellcor Common Stock
    per  share of P-B Common Stock offered  pursuant to the Merger Agreement. In
    addition, Goldman Sachs  analyzed the  consideration which  would have  been
    received  by holders of P-B Common Stock pursuant to the Merger Agreement at
    the 52-week high, low and average market prices of Nellcor Common Stock  for
    the  52-week  period  immediately  preceding  May  18,  1995.  Such analysis
    indicated that the consideration per share  of P-B Common Stock which  would
    have  been received pursuant to the Merger Agreement (x) at the 52-week high
    market price of  Nellcor Common  Stock was $39.82,  (y) at  the 52-week  low
    market  price of  Nellcor Common  Stock was $22.22,  and (z)  at the 52-week
    average market price of Nellcor Common Stock was $28.13.

        (ii)  SELECTED COMPANIES ANALYSIS.  Goldman Sachs reviewed and  compared
    certain  financial information relating to  Nellcor and P-B to corresponding
    financial information, ratios and public market multiples for seven publicly
    traded  corporations  in  the  medical  device  industry:  Ballard   Medical
    Products,  Marquette Electronics Inc.,  Protocol Systems, Inc., Respironics,
    Inc., SpaceLabs Medical, Inc., Tecnol Medical Products, Inc. and Vital Signs
    Inc. (the  "Selected Companies").  The  multiples of  Nellcor, P-B  and  the
    Selected  Companies were calculated  using the closing  prices of the Common
    Stock of  such companies  on  May 18,  1995  (the "Reference  Prices").  The
    multiples  and ratios  for each of  Nellcor, P-B and  the Selected Companies
    were based on

                                       31
<PAGE>
    publicly available  information  and composite  analyst  estimates.  Goldman
    Sachs'  analysis indicated that (x) the  median Reference Prices to earnings
    per share ratio (the  "P/E Ratio") for the  Selected Companies was 18.1x  in
    1994,  and was estimated to be 14.5x in  1995 and 12.4x in 1996, as compared
    with a 1994  P/E Ratio  for Nellcor  of 23.2  and estimated  P/E Ratios  for
    Nellcor  of 18.3x in 1995 and 14.4x in 1996, and a 1994 P/E Ratio for P-B of
    19.0x and estimated P/E Ratios for P-B  of 12.4x in 1995 and 10.8x in  1996;
    (y)  the median  multiples of  the Reference  Prices to  Last Twelve Months'
    ("LTM") sales, to LTM earnings before interest, taxes and depreciation,  and
    to  LTM earnings  before interest and  taxes ("EBIT") were  2.0x, 11.1x, and
    13.3x, respectively,  for the  Selected Companies,  2.4x, 9.2x,  and  12.5x,
    respectively,  for Nellcor and 1.2x,  10.4x, and 17.1x for  P-B; and (z) the
    median LTM gross  margin and  median LTM EBIT  margin was  55.8% and  12.3%,
    respectively, for the Selected Companies, 60.4% and 18.8%, respectively, for
    Nellcor and 41.6% and 7.0%, respectively, for P-B.

        (iii)    DISCOUNTED  CASH  FLOW ANALYSIS.    Goldman  Sachs  performed a
    discounted cash flow analysis of P-B  under the following two scenarios,  in
    each case using Nellcor management projections of P-B's future EBIT and free
    cash  flow:  (x)  without  taking  into  account  pre-tax  cost  savings and
    synergies reflected  in  the Synergies  Information  which may  be  realized
    following  the  Merger (the  "Without  Synergies Case"),  and  (y) including
    pre-tax cost savings and synergies projected by Nellcor and P-B managements,
    as reflected in the  Synergies Information (the  "Synergies Case"). In  such
    analysis, Goldman Sachs assumed terminal value multiples of 9x-14x 2000 EBIT
    and  discount rates  of 10%  to 18%.  For the  Without Synergies  Case, such
    analysis produced  implied  current per-share  values  of P-B  Common  Stock
    ranging  from  $21.3 to  $45.7, and  for the  Synergies Case,  such analysis
    produced implied current per-share values  of P-B Common Stock ranging  from
    $27.0 to $55.8.

         Goldman Sachs also performed a discounted cash flow analysis of Nellcor
    assuming terminal value multiples of 9x-14x 2000 EBIT and discount rates  of
    10%  to 18%.  Such analysis  indicated implied  current per-share  values of
    Nellcor Common Stock ranging from $39.1 to $68.8.

        (iv)  SELECTED  TRANSACTIONS ANALYSIS.   Goldman Sachs analyzed  certain
    public  information relating to selected  transactions in the medical device
    industry  since  1982  (the  "Selected  Transactions"),  and  compared  such
    information  to various multiples and ratios of the Merger, assuming a price
    of Nellcor Common  Stock of $43.00  per share (the  closing market price  of
    such  stock on May 18, 1995). Such  analysis indicated that for the Selected
    Transactions (x) aggregate consideration as  a multiple of LTM sales  ranged
    from 0.8x to 10.5x, with a mean of 2.8x and a median of 2.0x, as compared to
    a multiple of 1.7x for the Merger, (y) aggregate consideration as a multiple
    of  LTM net income ranged from  15.5x to 150.0x, with a  mean of 35.2x and a
    median of 29.1x, as compared to a multiple of 22.9x for the Merger, and  (z)
    aggregate consideration as a multiple of LTM EBIT ranged from 7.1x to 32.0x,
    with  a mean of  18.9x and a median  of 18.6x, as compared  to a multiple of
    19.6x for the Merger.

        (v)   PRO FORMA  MERGER  ANALYSIS.   Goldman  Sachs prepared  pro  forma
    analyses of the financial impact of the Merger. Using earnings estimates for
    Nellcor  and P-B prepared  by Nellcor management for  the years 1995 through
    2000, Goldman  Sachs compared  the  earnings per  share ("EPS")  of  Nellcor
    Common  Stock, on a standalone basis, to the  EPS of the common stock of the
    combined companies  on  a pro  forma  basis. Goldman  Sachs  performed  this
    analysis  based on a price of $43.00  per share of Nellcor Common Stock (the
    closing market  price of  such stock  on  May 18,  1995) under  the  Without
    Synergies  Case and  the Synergies  Case. Such  analyses indicated  that (x)
    under the Without Synergies Case the proposed transaction would be  dilutive
    to  Nellcor's stockholders on an earnings  per share basis in Nellcor fiscal
    years 1995  through 2000,  and (y)  under the  Synergies Case  the  proposed
    transaction  would be dilutive to Nellcor's  stockholders on an earnings per
    share basis in  Nellcor fiscal  year 1995  and accretive  in Nellcor  fiscal
    years 1996 through 2000.

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<PAGE>
        (vi)   CONTRIBUTION ANALYSIS.  Goldman Sachs reviewed certain historical
    and estimated future operating  and financial information (including,  among
    other  things, sales, EBIT, net income,  R&D spending, book value and market
    capitalization) for Nellcor, P-B and the pro forma combined entity resulting
    from the Merger. The analysis indicated that, based on the closing prices of
    Nellcor Common  Stock and  P-B Common  Stock on  May 18,  1995, the  Nellcor
    stockholders  would contribute  69% of the  outstanding market  value of the
    common equity of the  combined companies prior to  the Merger. The  analysis
    also  indicated that Nellcor would  contribute 65% of the  book value of the
    combined companies  after  the  merger.  Goldman  Sachs  also  analyzed  the
    relative  income statement contributions of Nellcor  and P-B to the combined
    companies on a pro forma basis (without taking into account the cost savings
    and synergies reflected  in the  Synergies Information)  for actual  Nellcor
    fiscal year 1994 and estimated Nellcor fiscal years 1995 through 1998, based
    on  financial  data  and  estimates provided  to  Goldman  Sachs  by Nellcor
    management. This analysis indicated that in Nellcor fiscal year 1995  (based
    on  fiscal  year-end  estimates),  Nellcor  would  have  contributed  43% to
    combined sales, 64% to combined EBIT, 63% to combined net income, and 57% to
    combined R&D  spending,  and in  Nellcor  fiscal years  1996  through  1998,
    Nellcor  would have contributed 45%, 46%  and 46%, respectively, to combined
    sales, 62%, 63% and 62%, respectively,  to combined EBIT, 62%, 63% and  62%,
    respectively, to combined net income, and 60%, 61% and 43%, respectively, to
    combined R&D spending.

        (vii)   OTHER ANALYSES.  Goldman Sachs also reviewed selected investment
    research reports  on,  and  earnings  estimates for,  Nellcor  and  P-B  and
    analyzed  available information regarding the current institutional holdings
    of Nellcor Common  Stock and P-B  Common Stock and  pro forma  institutional
    holdings  in the stock of  the pro forma combined  entity resulting from the
    Merger.

    The preparation  of a  fairness opinion  is  a complex  process and  is  not
necessarily  susceptible to  partial analysis or  summary description. Selecting
portions of the analyses or of the summary set forth above, without  considering
the  analyses  as a  whole, could  create  an incomplete  view of  the processes
underlying Goldman Sachs' opinion. In arriving at their fairness  determination,
Goldman  Sachs  considered  the results  of  all  such analyses.  No  company or
transaction used in the above analyses  as a comparison is identical to  Nellcor
or  P-B or the  contemplated transaction. The analyses  were prepared solely for
purposes of Goldman Sachs'  providing their opinion to  the Nellcor Board as  to
the  fairness to Nellcor of the Exchange  Ratio pursuant to the Merger Agreement
and do not purport to be appraisals  or necessarily reflect the prices at  which
businesses  or securities actually may be sold. Analyses based upon forecasts of
future results are not  necessarily indicative of  actual future results,  which
may  be significantly  more or less  favorable than suggested  by such analyses.
Because such analyses are  inherently subject to  uncertainty, being based  upon
numerous factors or events beyond the control of the parties or their respective
advisors,  none  of Nellcor,  P-B,  Goldman Sachs  or  any other  person assumes
responsibility if future results are materially different from those forecast.

    As described above, Goldman Sachs' opinion  to the Nellcor Board was one  of
many  factors  taken  into consideration  by  the  Nellcor Board  in  making its
determination to approve the  Merger Agreement. The  foregoing summary does  not
purport  to be a complete description of the analysis performed by Goldman Sachs
and is qualified by reference to the written opinion of Goldman Sachs set  forth
in Annex D hereto.

    Goldman Sachs, as part of their investment banking business, are continually
engaged  in the valuation of businesses  and their securities in connection with
mergers  and  acquisitions,  negotiated  underwritings,  competitive   biddings,
secondary  distributions of  listed and unlisted  securities, private placements
and valuations for estate, corporate and other purposes. Goldman Sachs have  not
participated  in the negotiations leading to the Merger Agreement, and have been
retained solely to provide a fairness  opinion. Goldman Sachs are familiar  with
Nellcor,  having provided  certain investment  banking services  to Nellcor from
time to  time,  including having  acted  as  managing underwriter  of  a  public
offering  of Nellcor Common Stock on May 19,  1987. In the course of the trading
activities of Goldman

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<PAGE>
Sachs and their affiliates, as of May 21, 1995, Goldman Sachs have accumulated a
long position of  73,500 shares of  Nellcor Common Stock  against which  Goldman
Sachs  was  short 18,039  shares  of Nellcor  Common Stock,  as  well as  a long
position of 217,500 shares of P-B Common Stock.

    Pursuant to  a  letter  agreement  dated April  28,  1995  (the  "Engagement
Letter"),  Nellcor engaged Goldman Sachs to  render the opinion of Goldman Sachs
with respect to the Exchange Ratio pursuant to the Merger Agreement. Pursuant to
the terms of the Engagement Letter, Nellcor has agreed to pay Goldman Sachs,  in
cash  upon delivery of their opinion, a fee of $600,000. Nellcor has also agreed
to  reimburse  Goldman  Sachs  for  their  reasonable  out-of-pocket   expenses,
including  attorney's  fees,  and  to indemnify  Goldman  Sachs  against certain
liabilities, including certain liabilities under the federal securities laws.

OPINION OF SMITH BARNEY

    Smith Barney  was  retained  by P-B  to  act  as its  financial  advisor  in
connection  with the Merger.  In connection with  such engagement, P-B requested
that Smith Barney evaluate the fairness, from a financial point of view, to  the
holders of P-B Common Stock of the Exchange Ratio. On May 19, 1995, Smith Barney
indicated  to  Mr. Dole  that it  would be  able to  deliver a  fairness opinion
regarding the Exchange Ratio. On May 21, 1995 Smith Barney delivered an  opinion
in  writing to the P-B Board to the effect  that, as of such date and based upon
and subject to the assumptions and qualifications set forth in such opinion, the
Exchange Ratio was fair, from a financial  point of view, to the holders of  P-B
Common Stock.

    In  arriving at its opinion, Smith  Barney reviewed the Merger Agreement and
held  discussions   with   certain   senior  officers,   directors   and   other
representatives  and  advisors  of P-B  and  certain senior  officers  and other
representatives and advisors of Nellcor concerning the business, operations  and
prospects  of P-B and Nellcor. Smith  Barney examined certain publicly available
business and  financial information  relating  to P-B  and  Nellcor as  well  as
certain  financial  forecasts  and other  data  for  P-B and  Nellcor  which was
provided to  Smith Barney  by the  respective managements  of P-B  and  Nellcor,
including   information  relating  to  certain  strategic  implications  of  and
operational benefits  anticipated from  the Merger.  Smith Barney  reviewed  the
financial  terms of the Merger as set  forth in the Merger Agreement in relation
to, among other things: current and historical market prices and trading volumes
of P-B  Common  Stock  and  Nellcor  Common  Stock;  the  respective  companies'
historical   and  projected  earnings;  and  the  capitalization  and  financial
condition or P-B and  Nellcor. Smith Barney considered,  to the extent  publicly
available,  the financial terms of  other similar transactions recently effected
that Smith  Barney considered  comparable  to the  Merger and  analyzed  certain
financial, stock market and other publicly available information relating to the
businesses   of  other  companies  whose   operations  Smith  Barney  considered
comparable to those  of P-B  and Nellcor. Smith  Barney also  evaluated the  pro
forma  financial impact of the Merger and  the relative contributions of P-B and
Nellcor to  selected pro  forma financial  data of  the combined  companies.  In
addition  to  the  foregoing, Smith  Barney  conducted such  other  analyses and
examinations and considered such other  financial, economic and market  criteria
as  Smith Barney deemed necessary  to arrive at its  opinion. Smith Barney noted
that its opinion was  necessarily based upon financial,  stock market and  other
conditions  and circumstances existing  and disclosed to Smith  Barney as of the
date of its opinion.

    In  rendering  its  opinion,  Smith  Barney  assumed  and  relied,   without
independent  verification, upon the  accuracy and completeness  of all financial
and other information publicly available  or furnished to or otherwise  reviewed
by or discussed with Smith Barney. With respect to financial forecasts and other
information provided to or otherwise reviewed by or discussed with Smith Barney,
Smith  Barney was advised by the respective  managements of P-B and Nellcor that
such  forecasts  and  other  information  were  reasonably  prepared  on   bases
reflecting   the  best  currently  available  estimates  and  judgments  of  the
respective managements of P-B  and Nellcor as to  the expected future  financial
performance  of P-B  and Nellcor  and as  to the  strategic implications  of and
operational benefits anticipated from the Merger. Smith Barney also relied, with
the consent of  the P-B  Board and  without independent  verification, upon  the
assessment  by the respective managements of  Nellcor and P-B concerning certain
litigation and contingencies with respect to Nellcor. Smith Barney assumed  that

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<PAGE>
the  Merger  will  be treated  as  a  pooling of  interests  in  accordance with
generally accepted accounting  principles and as  a tax-free reorganization  for
federal  income tax  purposes. Smith  Barney's opinion  relates to  the relative
value of P-B and Nellcor.  Smith Barney did not express  any opinion as to  what
the  value  of the  Nellcor Common  Stock actually  will be  when issued  to P-B
stockholders pursuant to  the Merger or  the price at  which the Nellcor  Common
Stock  will trade subsequent  to the Merger.  In addition, Smith  Barney did not
make or  obtain  an  independent  evaluation  or  appraisal  of  the  assets  or
liabilities  (contingent or  otherwise) of P-B  or Nellcor nor  did Smith Barney
make any physical  inspection of  the properties or  assets of  P-B or  Nellcor.
Smith  Barney's opinion does  not address the  relative merits of  the Merger as
compared to any alternative business strategies that might exist for P-B or  the
effect  of  any  other transactions  in  which  P-B might  engage.  In addition,
although Smith Barney evaluated the Exchange  Ratio from the financial point  of
view,  Smith  Barney  was  not  asked to  and  did  not  recommend  the specific
consideration payable in the Merger. No other limitations were imposed by P-B on
Smith Barney with respect to the  investigations made or procedures followed  by
Smith Barney in rendering its opinion.

    THE  FULL TEXT OF  THE WRITTEN OPINION  OF SMITH BARNEY  DATED MAY 21, 1995,
WHICH SETS FORTH THE ASSUMPTIONS MADE, MATTERS CONSIDERED AND LIMITATIONS ON THE
REVIEW UNDERTAKEN, IS ATTACHED HERETO AS  ANNEX E AND IS INCORPORATED HEREIN  BY
REFERENCE.  P-B STOCKHOLDERS  ARE URGED  TO READ  THIS OPINION  CAREFULLY IN ITS
ENTIRETY. SMITH  BARNEY'S  OPINION IS  DIRECTED  ONLY  TO THE  FAIRNESS  OF  THE
EXCHANGE  RATIO FROM A FINANCIAL POINT OF  VIEW AND HAS BEEN PROVIDED SOLELY FOR
THE USE OF THE P-B BOARD IN ITS  EVALUATION OF THE MERGER, DOES NOT ADDRESS  ANY
OTHER  ASPECT OF THE  MERGER OR RELATED  TRANSACTIONS AND DOES  NOT CONSTITUTE A
RECOMMENDATION TO ANY STOCKHOLDER AS TO HOW SUCH STOCKHOLDER SHOULD VOTE AT  THE
P-B  SPECIAL MEETING. THE  SUMMARY OF THE  OPINION OF SMITH  BARNEY SET FORTH IN
THIS PROXY STATEMENT/PROSPECTUS IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO THE
FULL TEXT OF SUCH OPINION.

    In preparing its opinion for the P-B Board, Smith Barney performed a variety
of financial  and comparative  analyses, including  those described  below.  The
summary  of such analyses does  not purport to be  a complete description of the
analyses underlying  Smith  Barney's  opinion. The  preparation  of  a  fairness
opinion is a complex analytic process involving various determinations as to the
most  appropriate and relevant methods of financial analyses and the application
of those methods to the particular circumstances and, therefore, such an opinion
is not readily susceptible to summary  description. In arriving at its  opinion,
Smith  Barney did not attribute any particular  weight to any analysis or factor
considered by it, but  rather made qualitative judgments  as to the  significant
and  relevance of each  analysis and factor.  Accordingly, Smith Barney believes
that such analyses must be considered as a whole and that selecting portions  of
such  analyses and factors,  without considering all  such analyses and factors,
could create a misleading  or incomplete view of  the processes underlying  such
analyses   and  its  opinion.  In  its  analyses,  Smith  Barney  made  numerous
assumptions  with  respect  to  P-B,  Nellcor,  industry  performance,   general
business,  economic, market and financial conditions  and other matters, many of
which are beyond the control of P-B and Nellcor. The estimates contained in such
analyses are not necessarily indicative of actual values or predictive of future
results or values, which may be significantly more or less favorable than  those
suggested  by  such analyses.  In addition,  analyses relating  to the  value of
businesses or  securities do  not purport  to be  appraisals or  to reflect  the
prices at which businesses or securities actually may be sold. Accordingly, such
analyses and estimates are inherently subject to substantial uncertainty.

    TRANSACTION  VALUATION SUMMARY.  As part of its transaction valuation, Smith
Barney performed an  analysis of revenues,  EBITDA, EBIT and  net income of  P-B
during fiscal year 1995 (actual) and fiscal year 1996 (forecasted) as a multiple
of:  (i) P-B's pre-offer market value of $343.2 million (based upon 13.1 million
fully diluted shares outstanding  and the closing per  share price of $26.25  on
May  19, 1995);  (ii) P-B's market  value at  the offer price  of $476.9 million
(based upon 13.1 million fully diluted shares outstanding and the offer price of
$36.30 per share (based on the closing sale price of Nellcor Common Stock on May
19, 1995 and the Exchange Ratio of  0.88)); and (iii) P-B's enterprise value  of
$556.1  million ($476.9 million  market value plus $79.2  million net debt). For
pre-offer market value,

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<PAGE>
the multiples were as follows: (i)  for fiscal year 1995: revenues 1.0x,  EBITDA
8.8x,  EBIT 14.5x and net income 23.6x; and (ii) for projected fiscal year 1996:
revenues 1.0x, EBITDA 6.2x, EBIT 8.6x and net income 12.6x. For market value  at
the  offer  price, the  multiples were  as  follows: (i)  for fiscal  year 1995:
revenues 1.4x, EBITDA  12.3x, EBIT  20.2x, and net  income 32.8x;  and (ii)  for
projected  fiscal  year 1996:  revenues 1.3x,  EBITDA 8.7x,  EBIT 12.0x  and net
income 17.5x.  For enterprise  value, the  multiples were  as follows:  (i)  for
fiscal  year 1995: 1.7x, EBITDA 14.3x, EBIT 23.6x and net income 38.2x; and (ii)
for projected fiscal year 1996: revenues 1.6x, EBITDA 10.1x, EBIT 14.0x and  net
income 20.4x.

    PUBLIC  AND PRIVATE  MARKET BREAKDOWN.   Smith Barney reviewed  with the P-B
Board the public  and private  market breakdown analysis  of P-B.  Based on  the
comparable  hospital equipment company, comparable home health care company, and
selected transaction analyses discussed below, Smith Barney explained to the P-B
Board that this analysis consisted of the valuation of each of P-B's significant
component business segments  (hospital equipment  and home  health care),  which
valuation  consists of an analysis of the  multiples at which companies in lines
of businesses  comparable to  such P-B  business segments  trade in  the  public
market  and have been acquired for in the private market. The combination of the
comparable hospital equipment  company and comparable  home health care  company
analyses  described in more  detail below generated  the following equity values
(based upon 13.0 million fully-diluted shares of P-B common stock  outstanding):
(i)  based upon fiscal  year 1995 EBIT:  range of approximately  $396 million to
$475 million in the aggregate, or approximately $30.43 to $36.46 per share; (ii)
based upon fiscal year 1995 revenues:  range of approximately $378.8 million  to
$458.1  million in the  aggregate, or approximately $29.04  to $35.12 per share;
and (iii) based  on implied fiscal  year 1996  net income by  segment: range  of
approximately  $389.6  million to  $449.3  million, or  approximately  $29.87 to
$34.44 per share. The comparable transactions analyses discussed below generated
an equity value of $28.50  to $36.50 per share  (based upon 13.0 million  fully-
diluted shares of P-B Common Stock outstanding). The above analysis utilized P-B
fiscal  years  ending  one month  after  the  calendar years  of  the comparable
companies.

    COMPARABLE HOSPITAL EQUIPMENT  COMPANY ANALYSIS.   Using publicly  available
information,  Smith Barney analyzed,  among other things,  the market values and
trading multiples  of P-B,  Nellcor and  the following  selected companies  (the
"Hospital  Comparable Companies")  in the  hospital equipment  industry: Acuson,
Beckman Instruments, Bio Rad Laboratories, Datascope Corporation, Elscint  Ltd.,
Infrasonics,  Marquette  Electronics  and Spacelabs  Medical  Inc.  Smith Barney
compared: (i) market values  as multiples of calendar  year 1994 net income  and
estimated  calendar year 1995 net income and (ii) adjusted market values (equity
market value, plus total debt, less cash)  as multiples of net revenue over  the
last  twelve months  ("LTM") and the  latest quarter annualized  net revenue and
EBIT. The  mean  and median  multiples  of calendar  year  1994 net  income  and
estimated  calendar year 1995  net income and LTM  and latest quarter annualized
net  revenue  and  EBIT  for   the  Hospital  Comparable  Companies   (excluding
Infrasonics)  were as follows:  (i) calendar year 1994  net income and estimated
calendar year 1995 net income  mean and median: 16.9x  and 16.3x, and 15.1x  and
13.5x, respectively; (ii) LTM and latest quarter annualized net revenue mean and
median: 1.9x and 0.9x, and 1.0x and 0.9x, respectively; and (iii) LTM and latest
quarter  annualized EBIT mean  and median: 12.0x  and 9.9x, and  11.5x and 8.4x,
respectively. Calendar year 1994 net income and estimated calendar year 1995 net
income and LTM and latest quarter annualized  net revenue and EBIT for P-B  were
as  follows: (i) calendar year 1994 net  income and estimated calendar year 1995
net  income:  22.4x  and  14.0x,  respectively;  (ii)  LTM  and  latest  quarter
annualized  net revenue: 1.2x  and 1.2x, respectively; and  (iii) LTM and latest
quarter annualized EBIT: 17.3x and  15.8x, respectively. Calendar year 1994  net
income  and estimated calendar year  1995 net income and  LTM and latest quarter
annualized net revenue and  EBIT for Nellcor was  as follows: (i) calendar  year
1994  net income and estimated  calendar year 1995 net  income: 24.8x and 18.4x,
respectively; (ii) LTM and latest quarter annualized net revenue: 2.1x and 1.9x,
respectively; and (iii) LTM and latest quarter annualized EBIT: 10.9x and  8.4x,
respectively.

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<PAGE>
    For  the Hospital Comparable Companies, Smith  Barney also analyzed the EBIT
margin, pre-tax margin, and net margin over the LTM and the latest quarter,  and
the  earnings per share ("EPS") growth for  calendar year 1994 and the estimated
EPS growth for calendar year 1995 and over five years. The mean and median  EBIT
margin, pre-tax margin and net margin for the LTM and the latest quarter for the
Hospital  Comparable Companies were as follows: (i) EBIT margin mean and median:
10.0% and 10.7% for the  LTM, and 10.0% and 11.0%  for the latest quarter;  (ii)
pre-tax margin mean and median: 10.5% and 10.0% for the LTM, and 10.5% and 10.6%
for  the latest quarter; and (iii) net margin mean and median: 7.1% and 6.4% for
the LTM, and 7.1% and 7.0% for the latest quarter. EPS growth for calendar  year
1994 and estimated EPS growth for calendar year 1995 and over five years for the
Hospital  Comparable Companies were  as follows: (i) mean  and median EPS growth
for calendar year  1994: 32.1%  and 16.0%,  respectively; (ii)  mean and  median
estimated  EPS growth for calendar year 1995: 15.6% and 16.8%, respectively; and
(iii) estimated EPS growth  for five years: 14.7%  and 14.5%, respectively.  The
EBIT  margin, pre-tax margin and  net margin for the  LTM and the latest quarter
for P-B was  as follows: (i)  EBIT margin: 7.0%  for the LTM,  and 7.3% for  the
latest  quarter; (ii) pre-tax margin: 5.7% for  the LTM, and 4.9% for the latest
quarter; and  (iii) net  margin:  4.3% for  the LTM,  and  4.5% for  the  latest
quarter. EPS growth for calendar 1994 and estimated EPS growth for calendar 1995
and  over five years for P-B were as  follows: (i) EPS growth for calendar 1994:
- -4.2%; (ii) estimated EPS growth for  calendar 1995: 59.7%; and (iii)  estimated
EPS growth for five years: 16.0%.

    COMPARABLE  HOME  HEALTH CARE  COMPANY ANALYSIS.   Using  publicly available
information, Smith Barney analyzed,  among other things,  the market values  and
trading  multiples of P-B and the following selected companies (the "Home Health
Care Comparable  Companies")  in  the  home  health  care  industry:  Healthdyne
Technologies,   Invacare  Corporation,  Respironics  and  Sunrise  Medical,  and
compared such multiples  against the multiples  of P-B implied  by the  Exchange
Ratio.  Smith Barney compared market values as multiples of, among other things,
calendar year 1994 net income and  estimated calendar year 1995 net income,  and
adjusted  market values  (equity market  value, plus  total debt,  less cash) as
multiples of net revenue over the LTM and the latest quarter annualized and EBIT
over the LTM and the latest quarter annualized. The mean and median multiples of
calendar year 1994 net  income and estimated calendar  year 1995 net income  and
LTM  and  latest  quarter  annualized  net revenue  and  EBIT  for  the Hospital
Comparable Companies were  as follows:  (i) calendar  year 1994  net income  and
estimated  calendar year 1995 net  income mean and median:  22.9x and 22.4x, and
18.1x and  18.5x,  respectively; (ii)  LTM  and latest  quarter  annualized  net
revenue  mean and median:  1.6x and 1.5x,  and 1.5x and  1.4x, respectively; and
(iii) LTM and latest quarter annualized  EBIT mean and median: 13.7x and  12.6x,
and  13.3x and 12.4x, respectively. Calendar  year 1994 net income and estimated
calendar year 1995 net income and LTM and latest quarter annualized net  revenue
and EBIT for P-B was as follows: (i) calendar year 1994 net income and estimated
calendar  year  1995 net  income: 22.4x  and 14.0x,  respectively; (ii)  LTM and
latest quarter annualized net  revenue: 1.2x and  1.2x, respectively; and  (iii)
LTM and latest quarter EBIT: 17.3x and 15.8x, respectively.

    For  the Home Health  Care Comparable Companies,  Smith Barney also analyzed
the EBIT margin,  pre-tax margin, and  net margin  over the LTM  and the  latest
quarter, and the EPS growth for calendar year 1994, and the estimated EPS growth
for  calendar year 1995  and over five  years. The mean  and median EBIT margin,
pre-tax margin and net margin  for the LTM and the  latest quarter for the  Home
Health  Care  Comparable Companies  were as  follows: (i)  EBIT margin  mean and
median: 12.2% and 10.5% for the LTM, and 12.1% and 10.7% for the latest quarter;
(ii) pre-tax margin mean and median: 11.5%  and 9.5% for the LTM, and 11.1%  and
9.2% for the latest quarter; and (iii) net margin mean and median: 7.3% and 5.8%
for  the LTM, and 6.8% and 5.5% for  the latest quarter. EPS growth for calendar
year 1994, estimated calendar year 1995 and over five years for the Home  Health
Care  Comparable Companies were as  follows: (i) mean and  median EPS growth for
calendar  year  1994  (excluding  Healthdyne  Technologies):  19.7%  and  18.7%,
respectively;  (ii) mean and median estimated  EPS growth for calendar year 1995
(excluding Healthdyne Technologies):  19.1% and 19.2%,  respectively; and  (iii)
estimated  EPS growth for five  years (excluding Healthdyne Technologies): 19.1%
and 18.4%, respectively. The EBIT margin, pre-tax margin and net margin for  the
LTM and the latest

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<PAGE>
quarter  for P-B was as follows: (i) EBIT margin: 7.0% for the LTM, and 7.3% for
the latest quarter;  (ii) pre-tax margin:  5.7% for  the LTM, and  4.9% for  the
latest  quarter; and (iii) net margin: 4.3% for the LTM, and 4.5% for the latest
quarter. EPS growth  for calendar year  1994, estimated calendar  year 1995  and
over  five years for P-B were as follows: (i) EPS growth for calendar year 1994:
- -4.2%; (ii)  estimated EPS  growth  for calendar  year  1995: 59.7%;  and  (iii)
estimated EPS growth for five years: 16.0%.

    ANALYSIS OF PREMIUMS PAID IN SELECTED STOCK-FOR-STOCK TRANSACTIONS INVOLVING
COMPANIES APPROXIMATELY EQUAL TO EACH OTHER IN SIZE.  Smith Barney also reviewed
stock-for-stock  transactions  involving companies  approximately equal  to each
other in  size.  Specifically,  Smith Barney  reviewed  the  following  mergers:
Northern  States  Power  Co./Wisconsin  Energy  Corp.;  Monk-Austin Inc./Dibrell
Brothers   Inc.;    Lockheed    Corp./Martin   Marietta    Corp.;    Blockbuster
Entertainment/Viacom   Inc.;  Care  Enterprises  Inc./Regency  Health  Services;
American Healthcare Mgmt./OrNda HealthCorp.; Medical Care America  Inc./Surgical
Care  Affiliates Inc.; HCA Hospital  Corp. of America/Columbia Healthcare Corp.;
KeyCorp/Society Corp.; Price  Co./Costco Wholesale  Corp.; Inforum  Inc./MEDSTAT
Systems;   Critical  Care   America  Inc./Medical  Care   Int'l  Inc.;  Advanced
Telecommunications/LDDS Communications; Cetus Corp./Chiron Corp.;  Manufacturers
Hanover  Corp./Chemical Banking  Corp.; and Ocean  Drilling & Exploration/Murphy
Oil Corp. Smith  Barney reviewed the  percentage premiums of  offer values  over
market  values one day prior, one month prior, two months prior and three months
prior to the announcement date. The mean and median percentage premiums were  as
follows: (i) one day prior: 17.3% and 15.2%, respectively; (ii) one month prior:
23.4%  and  18.9%,  respectively;  (iii)  two  months  prior:  29.3%  and 19.6%,
respectively; and (iv) three months prior: 28.2% and 17.0%, respectively.

    ANALYSIS OF  SELECTED  MEDICAL  DEVICES TRANSACTIONS.    Smith  Barney  also
reviewed the purchase price as a multiple of LTM net income, book value, and LTM
cash  flow  (cash  flow  calculated  as LTM  net  income  plus  depreciation and
amortization ("D&A"); and the transaction value  as a multiple of LTM  revenues,
LTM  EBITDA and LTM  EBIT for recent  medical device transactions. Specifically,
Smith Barney reviewed the following medical device transactions: Mitek  Surgical
Products  Inc./Johnson & Johnson; IVAC Corp. (Eli Lilly & Co.)/River Acquisition
Corp.; SciMed Life Systems Inc./Boston Scientific Corp.; NAMIC USA  Corp./Pfizer
Inc.;   Cardiovascular  Imaging   Systems/Boston  Scientific   Corp.;  Diasonics
Ultrasound/Elbit  Ltd.;  Sterling  Winthrop-Medical  Imaging/Hafslund   Nycomed;
Siemens    AG   Pacemaker    Unit/St.   Jude    Medical;   Corometrics   Medical
Systems/Marquette Electronics  Inc.  USA;  DLP  Inc./Medtronic  Inc.;  Interspec
Inc./Advanced  Technologies Laboratories Inc.;  Webster Laboratories Inc./Cordis
Corp.; Stuart  Medical Inc./Owens  &  Minor Inc.;  Electromedics  Inc./Medtronic
Inc.;  Edward  Weck  Inc./Teleflex Inc.;  Costar  Corp./Corning  Inc.; DeVilbiss
Health Care/Sunrise  Medical Inc.;  Applied Immune  Sciences Inc./Rhone  Poulenc
Rorer   Inc.;  Nicolet  Instrument-Biomed.  Instruments/Thermo  Electron  Corp.;
Tracheostomy  Products/Mallindrodt   Medical  (IMCERA   Group  Inc.);   Sybiosis
Corp./American  Home Products  Corp; Intertech  Resources Inc./Smiths Industries
PLC;  Surgitek  (Bristol  Meyers-Squibb   Corp.)/Cabot  Medical  Corp.;   Origin
Medsystems  Inc./Eli Lilly & Co.; Shiley Inc.-Product Lines/Sorin Biomedica SpA;
Bio-Electro Systems Inc./ALZA Corp.; Pfizer Hospital
Products-(Deknatel)/Investor Group; International Teledyne Corp./Thermo Electron
Corp.; Micro-Controle  SA-Micro Positioning  Operations/Newport BV;  Bio-Medicus
Inc./Medtronic;    Concept   Inc./Bristol    Myers   Squibb    Co.;   and   COBE
Laboratories/Gambro AB.  With  respect to  the  above listed  transactions,  the
purchase  price multiples were  as follows: (i)  LTM net income:  mean of 29.0x,
with a high of 48.3x  and a low of  8.1x; (ii) book value:  mean of 3.4x with  a
high  of 7.6x and a low  of 0.8x; and (iii) LTM cash  flow: mean of 21.0x with a
high of 59.1x and a low of 9.3x. With respect to the above listed  transactions,
the  transaction value multiples were as follows: (i) LTM revenues: mean of 2.6x
with a high of 8.7x  and a low of  0.2x; (ii) LTM EBITDA:  mean of 11.9x with  a
high  of 19.8x and a low of 6.4x; and  (iii) LTM EBIT: mean of 16.1x with a high
of 27.0x and  a low of  4.9x. The premiums  paid (calculated off  the price  one
month  prior to  announcement date) in  the above  numerated transactions ranged
from a high of 102.7% to a low of 25.8%, with a mean of 58.1%.

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<PAGE>
    ANALYSIS OF SELECTED HOME CARE TRANSACTIONS.  Smith Barney also reviewed the
purchase price as a multiple  of LTM net income, book  value, and LTM cash  flow
(cash  flow calculated as LTM net income plus D&A); and the transaction value as
a multiple of LTM revenues, LTM EBITDA and LTM EBIT for recent home health  care
transactions.  Specifically,  Smith Barney  reviewed  the following  recent home
health care transactions: Abbey Healthcare Group Inc./Homedco Group Inc.; Cooper
Holding Corp./Integrated Health  Services; Home  Nutritional Services  Inc./W.R.
Grace  & Co.; Protocare Inc./ Abbey Healthcare Group Inc.; Critical Care America
Inc./Caremark International Inc.; Patient Care Inc./Chemed Corp.; American  Home
Therapies  Inc./Medisys Inc.; Lifetime  Corp./Olsten Corp.; Medical Innovations,
Inc./Ballard Medical Products; Home Intensive  Care, Inc./W.R. Grace & Co.;  The
IV  Clinic,  Inc./Quantum  Health  Resources; Allcare  Health  Services,  Inc. &
Allcare Home Care  Inc./ Medisys, Inc.;  Advance Home Health  Services, Inc./  &
Diversified  Diagnostics/Lincare Holdings, Inc.;  Total Home Care, Inc./Curaflex
Health Services; TPN  Lifeline, Inc./Home  Intensive Care,  Inc.; Critical  Care
America,  Inc./Medical  Care International;  Lorimax,  Inc./Total Pharmaceutical
Care, Inc.;  Glasrock  Home  Health Care,  Inc./Homedco  Group,  Inc.;  CareLink
Corp./Tokos  Medical Corp.;  Home Health  Depot, Inc./Curaflex  Health Services,
Inc.;  Preferred  Homecare  of   America/Home  Intensive  Care  Inc.;   TeamCare
Inc./Critical  Care  America, Inc.;  Meyer Care  SF,  Inc./In Home  Health Inc.;
Medical Research Management Inc./Tokos Medical Corp.; CareLine, Inc./Care  Group
Inc.;  Comprehensive Home Services/Quantum Health  Resources; Care Plus Inc./New
England Critical Care; Greater New York Home Therapeutics Inc./T2 Medical;  Care
Plus  Inc./New England Critical Care Inc.; Upjohn Healthcare Services/The Olsten
Corporation; Mentor Clinical Care/Lifetime Corp.; Fairfield Home Therapeutics/T2
Medical; and  Athens Home  Therapeutics/T2 Medical.  With respect  to the  above
listed  transactions, the purchase price multiples  were as follows: (i) LTM net
income: mean of 23.2x, with a high of 44.7x and a low of 2.6x; (ii) book  value:
mean  of 8.0x with a high  of 22.5x and a low of  1.6x; and (iii) LTM cash flow:
mean of 17.0x with a high of 35.4x and a low of 2.6x. With respect to the  above
listed  transactions, the transaction  value multiples were  as follows: (i) LTM
revenues: mean of 2.1x with a high of  6.9x and a low of 0.1x; (ii) LTM  EBITDA:
mean  of 12.4x with a high of 26.9x and  a low of 2.2x; and (iii) LTM EBIT: mean
of 17.2x with a high of 49.3x and  a low of 2.2x. The premiums paid  (calculated
off  the  price  one month  prior  to  announcement date)  in  the  above listed
transactions ranged from  a high of  118.5% to a  low of -5.4%,  with a mean  of
62.5%.

    No  company or  transaction used  in the above  analyses as  a comparison is
identical to  P-B,  Nellcor or  the  contemplated transaction.  Accordingly,  an
analysis  of  the  results of  the  foregoing  is not  mathematical;  rather, it
involves  complex  considerations  and   judgments  concerning  differences   in
financial  and operating characteristics of the companies and other factors that
could affect the public trading value of  the companies to which they are  being
compared.

    BREAK-UP ANALYSIS.  Smith Barney reviewed and analyzed the critical care and
home  health  care  segments of  P-B  to determine  the  range of  values  for a
hypothetical sale of P-B by business segment. The segment valuations were  based
on  (i) the comparable  company analyses for each  segment described above; (ii)
the  precedent  transaction  analyses  described  above;  and  (iii)  additional
information  provided to Smith  Barney by P-B concerning  P-B's investment in an
intra-arterial blood gas monitoring  system ("FOxS") and the  tax basis of  each
segment.   Based  upon  such  information,  the  break-up  analysis  takes  into
consideration, among other factors, the valuation of the segments, the tax basis
of the segments and the potential tax benefits from P-B's existing net operating
losses ("NOLs") and the  potential NOLs generated by  the hypothetical sale  for
the purpose of this analysis. The analysis assumes the sale of the critical care
segment  and the FOxS technology,  followed by the sale  of the home health care
segment, to maximize potential value. The analysis yielded a range of $28.82  to
$37.17  per  share of  P-B Common  Stock, before  taking into  consideration the
timing of  such a  potential transaction  and the  effects of  such a  potential
transaction  on the operations of  P-B, and the possibility  that some or all of
the hypothetical sale could not be completed.

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<PAGE>
    EXCHANGE RATIO ANALYSIS.  Smith Barney reviewed and analyzed the  historical
ratio  of the daily closing prices of P-B  Common Stock for the LTM. The average
of the exchange ratios  of the daily  closing price of one  share of P-B  Common
Stock  to one  share of  Nellcor Common  Stock during  such period  was 0.66, as
compared to the Exchange Ratio of 0.88.

    CONTRIBUTION ANALYSIS.  Smith Barney analyzed the relative contributions  of
P-B  and  Nellcor to  the sales,  EBITDA, EBIT  and net  income of  the combined
company for fiscal years  1992, 1993, 1994 and  1995 and projected fiscal  years
1996,  1997, 1998 and 1999. For purposes  of such analysis, the P-B contribution
was adjusted for certain non-recurring write-offs and restructuring charges  and
was  conformed to  Nellcor's fiscal year  end. P-B and  Nellcor projections were
based upon management  projections of each  of P-B and  Nellcor for fiscal  year
1996,  which  were  extrapolated by  Smith  Barney  with the  assistance  of the
respective managements of P-B and Nellcor for fiscal years 1997, 1998 and  1999.
This  analysis  indicated  that  (i)  for  fiscal  year  1992,  P-B  would  have
contributed approximately 59% of sales,  44% of EBITDA, 40%  of EBIT and 44%  of
net  income, and Nellcor would have  contributed approximately 41% of sales, 56%
of EBITDA, 60% of  EBIT and 56% of  net income, (ii) for  fiscal year 1993,  P-B
would  have contributed approximately 58%  of sales, 46% of  EBITDA, 45% of EBIT
and 47% of net income, and  Nellcor would have contributed approximately 42%  of
sales,  54% of EBITDA, 55% of EBIT and  53% of net income, (iii) for fiscal year
1994, P-B would have contributed approximately 58% of sales, 44% of EBITDA,  42%
of  EBIT and 40% of net income, and Nellcor would have contributed approximately
42% of sales, 56% of EBITDA, 58% of EBIT and 60% of net income, (iv) for  fiscal
year 1995, P-B would have contributed approximately 57% of sales, 39% of EBITDA,
37%  of  EBIT  and  38%  of  net  income,  and  Nellcor  would  have contributed
approximately 43% of sales, 61%  of EBITDA, 63% of EBIT  and 62% of net  income,
(v)  for projected fiscal  year 1996, P-B would  contribute approximately 56% of
sales, 42% of  EBITDA, 41%  of EBIT  and 42% of  net income,  and Nellcor  would
contribute approximately 44% of sales, 58% of EBITDA, 59% of EBIT and 58% of net
income,  (vi) for projected fiscal year 1997, P-B would contribute approximately
56% of sales,  41% of EBITDA,  41% of EBIT  and 43% of  net income, and  Nellcor
would  contribute approximately 44% of sales, 59% of EBITDA, 59% of EBIT and 57%
of net  income, (vii)  for  projected fiscal  year  1998, P-B  would  contribute
approximately  56% of sales, 42%  of EBITDA, 42% of EBIT  and 44% of net income,
and Nellcor would contribute approximately 44%  of sales, 58% of EBITDA, 58%  of
EBIT  and 56% of  net income, (viii)  for projected fiscal  year 1999, P-B would
contribute approximately 56% of sales, 42% of EBITDA, 42% of EBIT and 44% of net
income, and Nellcor would contribute approximately 44% of sales, 58% of  EBITDA,
58%  of EBIT and  56% of net  income. Immediately following  consummation of the
Merger, based upon  the Exchange  Ratio and 13.1  million P-B  and 17.5  million
Nellcor  fully-diluted total shares outstanding, stockholders of P-B and Nellcor
would  own  approximately  39.8%  and  60.2%,  respectively,  of  the   combined
companies.

    DISCOUNTED  CASH FLOW  ANALYSIS.  Smith  Barney performed  a discounted cash
flow analysis of the projected free cash flow of P-B for the fiscal years  ended
1996  through 1999,  based on management  projections for fiscal  years 1996 and
1997 and then extrapolated by Smith Barney with the assistance of P-B management
for fiscal years 1998 and 1999. For comparative purposes, Smith Barney utilized,
in such analysis, discount rates of 10%, 15% and 20% and terminal year multiples
of EBITDA of 11.0x, 12.0x  and 13.0x, but focused on  a discount rate of 15%  in
its  valuation calculations. Based upon a discount rate of 15% and terminal year
multiples of EBITDA of 11.0x, 12.0x and 13.0x, Smith Barney arrived at an equity
valuation reference range for P-B of approximately $382 million to $453  million
(or  approximately $30.41 to $36.02 per share  of P-B Common Stock) based on the
management projections.

    PRO FORMA MERGER ANALYSIS.   Smith Barney analyzed  the pro forma impact  of
the  Merger on the  projected EPS of  Nellcor for the  fiscal years 1995 through
1999. Based on fully diluted EPS estimates  for Nellcor of $2.08 in 1995,  $2.37
in  1996, $2.72 in 1997, $3.11 in 1998  and $3.54 in 1999, and fully diluted EPS
estimates for P-B of $1.67 in 1995, $2.31 in 1996, $2.72 in 1997, $3.30 in  1998
and  $3.70 in 1999, and an Exchange Ratio  of 0.88, the results of the pro forma
merger analysis suggest  that the  merger would be  dilutive to  Nellcor EPS  in
fiscal    year   1995   and    accretive   in   fiscal    years   1996   through

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<PAGE>
1999, regardless of whether synergies are achieved for fiscal years 1996 through
1999. The  actual  results  achieved  by the  combined  company  may  vary  from
projected results and the variations may be material.

    OTHER  FACTORS AND  COMPARATIVE ANALYSIS.   In rendering  its opinion, Smith
Barney also considered other factors  and conducted other comparative  analyses,
including  a review  of (i) the  history of  trading prices and  volumes for P-B
Common Stock and Nellcor Common Stock;  (ii) Nellcor's cash position; and  (iii)
the pro forma ownership of the combined companies.

    The terms of the engagement of Smith Barney by P-B are set forth in a letter
agreement  dated September  27, 1994  between Smith  Barney and  P-B (the "Smith
Barney Engagement Letter"). Pursuant to the terms of the Smith Barney Engagement
Letter, P-B became obligated to pay  an aggregate of approximately $3.8  million
in  fees to Smith  Barney on April  6, 1995 (including  certain amounts that had
become payable  or were  paid  prior to  such date)  as  a result  of  financial
advisory  services provided  to P-B  in connection  with an  earlier unsolicited
tender offer for P-B Common Stock  by Thermo Electron. In addition, pursuant  to
the  terms  of the  Smith  Barney Engagement  Letter,  upon consummation  of the
Merger, a transaction fee will become payable to Smith Barney in an amount equal
to (a) the Applicable  Percentage (as defined below)  of (i) the total  proceeds
and other consideration paid or received or to be paid or received in connection
with  the Merger  (based, in the  case of  Nellcor Common Stock,  on the average
closing price of Nellcor  Common Stock for  the five trading  days prior to  the
closing  of  the Merger)  plus (ii)  long-term  indebtedness for  money borrowed
assumed in the Merger (the  sum of (i) and  (ii) being the "Transaction  Value")
less (b) all fees that are otherwise paid or payable to Smith Barney pursuant to
its  engagement by P-B including advisory  fees, retainer fees, opinion fees and
defense advisory fees, but excluding amounts paid or payable in respect of P-B's
obligation to  indemnify  Smith  Barney or  in  reimbursement  of  out-of-pocket
expenses  of Smith Barney.  For purposes of  the preceding sentence, "Applicable
Percentage" means: (1) 1%  for Transaction Values of  $500,000,000 or more,  (2)
between  1%  and 1.25%  for  Transaction Values  of  less than  $500,000,000 but
greater than or  equal to  $200,000,000 (the Applicable  Percentage within  such
interval  increasing from  1% to  1.25% proportionately  to the  decrease in the
Transaction Value), and (3) up to 2% (based on a schedule contained in the Smith
Barney Engagement Letter)  for Transaction  Values below  $200,000,000. P-B  has
also  agreed to reimburse Smith Barney for its out-of-pocket expenses, including
all fees and disbursements of counsel, and to indemnify Smith Barney and certain
related persons against certain liabilities in connection with their engagement,
including certain liabilities under the federal securities laws.

    The portion of  the fees  payable to Smith  Barney that  is contingent  upon
consummation  of  the Merger  is currently  estimated  to be  approximately $2.1
million based upon an estimated Transaction Value of approximately $618  million
multiplied by an Applicable Percentage of 1%, less the $4.1 million in fees that
were paid or became payable prior to the Merger. The estimated Transaction Value
was  calculated assuming (solely for the  purpose of such estimation) an average
stock price of $48.00 per share of Nellcor Common Stock, and using the number of
P-B's fully diluted shares outstanding (treasury method) as of June 30, 1995 and
P-B's long-term indebtedness  as of June  30, 1995. The  actual amount could  be
higher  or lower, based upon  Nellcor's stock price, the  number of P-B's fully-
diluted shares  outstanding (treasury  method)  and the  amount of  P-B's  total
long-term indebtedness immediately prior to the Merger.

    Smith  Barney is  a nationally  recognized investment  banking firm  and was
selected by P-B based on Smith  Barney's experience and expertise. Smith  Barney
regularly  engages  in  the  valuation of  businesses  and  their  securities in
connection with mergers and acquisitions, negotiated underwritings,  competitive
bids,  secondary  distributions  of  listed  and  unlisted  securities,  private
placements and valuations of estate, corporate and other purposes.

    Smith Barney has advised  P-B that, in the  ordinary course of business,  it
may  actively trade debt  and equity securities  of P-B and  Nellcor for its own
account or for the account of its customers and,

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<PAGE>
accordingly, may at any time hold a  long or short position in such  securities.
In  addition, Smith Barney and its  affiliates (including The Travelers Inc. and
its affiliates) may maintain business relationships with P-B.

INTERESTS OF CERTAIN PERSONS IN THE MERGER

    In considering the recommendations  of the Nellcor Board  and the P-B  Board
with  respect to the Merger Agreement and the transactions contemplated thereby,
stockholders should be aware that certain  members of the management of  Nellcor
and  P-B have interests in  the Merger that are in  addition to the interests of
stockholders of Nellcor and P-B generally.

    EMPLOYMENT AGREEMENTS.  In the Merger Agreement, Nellcor has agreed that  it
will  offer to  Burton A.  Dole, Jr.,  an employment  agreement, which  would be
effective from and  after the closing  of the Merger.  The employment  agreement
with  Mr. Dole will provide for  an initial term of two  years in which Mr. Dole
shall serve as the Chairman of the Board of Directors of the combined companies.
As Chairman, Mr.  Dole will  chair meetings  of the  Board of  Directors of  the
combined  companies, the agenda for and the conduct  of which will be set by the
President and Chief Executive Officer of the combined companies. The  employment
agreement  also will provide for an additional  term of seven and one-half years
during which  Mr. Dole  shall serve  as an  employee with  more limited  duties.
During  his two years  as Chairman of  the Board of  the combined companies, Mr.
Dole shall be entitled to receive a  salary of $250,000 per year and during  his
seven and one-half year term he shall be entitled to receive a salary of $44,000
per year.

    Mr.  Dole's employment  agreement will  also provide  for certain additional
employee benefits including severance  payments upon certain termination  events
and  "gross up" payments should Mr. Dole  become liable for certain excise taxes
by reason of his receipt of  any "excess parachute payments" under the  Internal
Revenue Code of 1986, as amended (the "Code").

    In  addition, Mr. Dole's employment with  P-B will terminate on consummation
of the Merger and,  as a result,  Mr. Dole will be  entitled to receive  certain
severance  payments  pursuant  to  the terms  of  his  existing  1980 employment
agreement with P-B. See  "-- Severance Arrangements." Under  the terms of  P-B's
Supplemental  Early Retirement Plan (the "SERP"), Mr. Dole will receive payments
in an amount  equal to  $23,083 per  month for life  (based on  a straight  life
annuity,  although Mr. Dole may elect a  different form of payment to the extent
provided in the  SERP), subject to  reduction to the  extent other payments  are
made to Mr. Dole under P-B's Defined Benefit Pension Plan or Make Up Plan.

    In  the Merger Agreement, Nellcor  has agreed that it  will offer to John H.
Morrow an  employment agreement,  which upon  the closing  of the  Merger,  will
supersede  Mr. Morrow's existing employment  agreement. The employment agreement
with Mr. Morrow  will provide  that Mr.  Morrow is  to serve  as Executive  Vice
President  of the  combined companies and  President of  the combined companies'
Home Health Care Business, including its Aero Systems business and its  Republic
of Ireland facilities. Pursuant to the employment agreement, Mr. Morrow would be
entitled  to an initial  salary of $275,000  per annum plus  an initial targeted
bonus in  the amount  of  50% of  his base  salary,  subject to  achievement  of
individual  and company objectives. Mr. Morrow's salary and bonus are subject to
periodic review and adjustment  pursuant to Nellcor's  policies with respect  to
other similarly situated executives. Mr. Morrow's employment agreement will also
provide  for certain  additional employee benefits  including severance payments
upon certain termination events and "gross up" payments should Mr. Morrow become
liable for  certain  excise  taxes by  reason  of  his receipt  of  any  "excess
parachute payments" under the Code. See "-- Severance Arrangements."

    Mr.  Morrow's employment agreement with  Nellcor will provide a Supplemental
Retirement Benefit Plan (the "Nellcor SERP")  in lieu of his rights under  P-B's
SERP,  the terms of which will generally be based upon P-B's SERP. The amount of
benefits payable under the Nellcor SERP  will depend upon a variety of  factors,
including  Mr. Morrow's  compensation and  bonus levels  prior to  the time that
payments under the Nellcor SERP become available.

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<PAGE>
    STOCK OPTION  PLANS  AND RESTRICTED  STOCK.   By  the  terms of  P-B's  1979
Employee  Stock Benefit Plan, all options  issued thereunder have vested. By the
terms of P-B's 1988  Stock Benefit Plan, the  vesting and exercisability of  all
stock  options outstanding thereunder will accelerate effective 30 days prior to
the date of the Merger, and such options will terminate upon consummation of the
Merger. All restricted stock  issued thereunder will  vest upon consummation  of
the  Merger. Nellcor has agreed in the  Merger Agreement that it will substitute
replacement options for any P-B stock  options outstanding under the 1988  Stock
Benefit  Plan  and the  1979  Employee Stock  Benefit  Plan that  have  not been
exercised as  of the  date  of the  Merger  including accelerated  options  that
terminate  as a result of the Merger. Such replacement options shall entitle the
holder thereof  to  purchase that  number  of  shares of  Nellcor  Common  Stock
(rounded  up to the  nearest whole share) equal  to the number  of shares of P-B
Common Stock subject to the replaced option multiplied by the Exchange Ratio, at
an exercise price per share of Nellcor Common Stock (rounded down to the nearest
penny) equal to the former  exercise price per share  of P-B Common Stock  under
such  option immediately prior to  the Merger divided by  the Exchange Ratio. In
general, all  substituted options  to  purchase Nellcor  Common Stock  shall  be
subject  to the same terms and conditions  as were applicable to the expired P-B
Stock Options for  which they are  substituted except that  the acceleration  of
vesting and exercisability as a result of the Merger shall not be given effect.

    The  substitution of such  options enables participants  in P-B's 1988 Stock
Benefit Plan  and 1979  Employee Stock  Benefit Plan  to hold  stock options  to
acquire  Nellcor Common Stock after the  Merger rather than having their options
terminate upon consummation of the Merger. In addition, certain employees of P-B
including Mr. Dole and  Mr. Morrow hold incentive  stock options under the  1988
Stock Benefit Plan in amounts that would cause a portion of such incentive stock
options  to become  non-qualified stock options  upon the  acceleration of their
vesting and  exercisability  in  connection with  the  Merger.  The  substituted
Nellcor  incentive stock  options provided  for in  the Merger  Agreement enable
these employees to  retain the  tax benefits associated  with holding  incentive
stock options.

    As  of July 19, 1995, employees (or former employees) of P-B held options to
purchase an  aggregate of  883,583 shares  of  P-B Common  Stock at  a  weighted
average  exercise price  of $22.13  per share  (at exercise  prices ranging from
$9.88 to $29.75 per  share). Approval of the  1995 Merger Stock Incentive  Plan,
pursuant  to  which  the  Nellcor  options will  be  issued  in  substitution or
assumption of P-B options under P-B's 1988 Stock Benefit Plan and 1979  Employee
Stock Benefit Plan, requires the affirmative vote of the holders of the majority
of  the shares of Nellcor Common Stock  present, or represented, and entitled to
vote at  the  Nellcor  Special  Meeting. See  "The  Nellcor  1995  Merger  Stock
Incentive Plan."

    SEVERANCE  ARRANGEMENTS.   P-B and Nellcor  have mutually  agreed that, upon
consummation of the Merger, Mr. Dole will  be terminated under the terms of  his
current  employment agreement with  P-B dated April 25,  1980, and in connection
with such termination Mr. Dole shall  be entitled to receive severance  payments
at  the  rate of  his  total annual  base  salary (which  is  an annual  rate of
$340,000) payable  for the  remaining  term of  his  April 25,  1980  employment
agreement (which will be approximately 56 months if the Merger is consummated on
September  1, 1995). Such  severance payments will  be paid over  a period of 90
months, in accordance with the terms of Mr. Dole's 1980 employment agreement. In
addition, Nellcor's employment agreement with Mr. Dole will provide that if  Mr.
Dole's  employment with Nellcor  is terminated (other than  on account of death,
disability or for  cause) or if  Mr. Dole terminates  such employment  agreement
with  Nellcor in  certain circumstances  constituting good  reason, he  shall be
entitled to receive among other things (i)  the balance of payments to which  he
is  entitled  under  his employment  agreement  with Nellcor,  and  (ii) certain
additional payments with respect  to the foregone value  of his incentive  stock
options.  In addition,  Mr. Dole's employment  agreement with  Nellcor also will
entitle him to  "gross-up" payments should  Mr. Dole become  liable for  certain
excise  taxes by reason of  his receipt of amounts, if  any, from Nellcor or P-B
constituting "excess parachute payments" under the Code.

    If Mr. Morrow's employment with Nellcor is terminated (other than on account
of death, disability or  for cause) or if  Mr. Morrow terminates his  employment
with  Nellcor under certain circumstances constituting  good reason, he shall be
entitled   to    receive,    among    other   things,    (i)    severance    pay

                                       43
<PAGE>
for  a period of three  years from his employment  termination date at an annual
rate equal to the sum of (a) his highest base salary rate from Nellcor in effect
prior to the employment termination date, plus (b) the highest bonus paid to him
under Nellcor's short-term  incentive bonus  program for any  fiscal year,  (ii)
certain  additional payments with respect to the foregone value of his incentive
stock options, and (iii) additional "gross-up" payments should he become  liable
for  certain excise  taxes by  reason of  his receipt  of amounts,  if any, from
Nellcor or P-B constituting "excess parachute payments" under the Code.

    In June 1994, P-B entered into an Executive Agreement with Mr. Morrow, which
was supplemented in November 1994. In November 1994, P-B entered into  Executive
Agreements with Messrs. Doyle, Jones, Rankin and Niles, each of whom is a senior
executive  of  P-B, and  entered into  Severance  Agreements with  12 additional
persons who were  then officers  of P-B  (Messrs. Jonietz,  Ross, Neal,  Fettes,
Hope,  Stewart,  Robbins,  Treff,  Miller,  Woodring,  Gaskin  and  Reller). P-B
subsequently entered into a Severance Agreement with one additional officer (Mr.
Stowell). The  Executive  Agreement  with  Mr. Morrow  is  being  superseded  in
connection with his employment agreement with Nellcor.

    The   Executive  Agreements  generally  provide   that  if  the  executive's
employment is terminated  (other than  on account  of death,  disability or  for
cause)  or if  the executive  terminates such  employment agreement  with P-B in
certain circumstances constituting good reason, the executive shall be  entitled
to  receive among other things (i) salary  and bonus continuation payments for a
period of up to three years, (ii) a one-time bonus (based on the average  annual
bonus  paid to such executive over the last  three years) pro rated for the year
of termination if the executive is not otherwise entitled to receive a bonus for
such year, and (iii) the acceleration of the executive's unvested stock  options
and  restricted stock awards. Amounts payable under the Executive Agreements are
not dependent upon the occurrence of a change in control, except that the salary
and bonus amounts referred to in (i) and (ii) shall be paid in a lump sum amount
if the termination of  the executive's employment occurs  within two years of  a
change of control (which, as defined, would include the Merger).

    The  Severance Agreements generally provide that if the officer's employment
is terminated (other than on  account of death, disability  or for cause) or  if
the   officer  terminates  such   employment  agreement  with   P-B  in  certain
circumstances constituting  good reason,  in each  case within  two years  of  a
change in control (which as defined would include the Merger), the officer shall
be  entitled to  receive among  other things  (i) salary  and bonus continuation
payments for a  period of  up to  two years, and  (ii) the  acceleration of  the
officer's unvested stock options.

    INDEMNIFICATION  AND INSURANCE.   Under the  terms of  the Merger Agreement,
Nellcor and the Surviving Corporation have  each agreed that for acts  occurring
prior  to  the  Merger (i)  all  rights  to indemnification  and  advancement of
expenses  existing  in  favor  of  the  directors  and  officers  of  P-B   (the
"Indemnified  Parties") under the provisions existing  on the date of the Merger
Agreement  in   the  Restated   Certificate   of  Incorporation,   By-Laws   and
indemnification agreements of P-B shall survive the Merger, and (ii) Nellcor and
the  Surviving  Corporation shall  each indemnify  and  advance expenses  to the
Indemnified  Parties  to  the  full  extent  required  or  permitted  under  the
provisions  existing  on  the  date  of the  Merger  Agreement  in  the Restated
Certificate of Incorporation, By-Laws and indemnification agreements of P-B.

    Nellcor has also agreed  to maintain, for  a period of  six years after  the
Merger,  with  respect to  claims arising  from facts  or events  which occurred
before the Merger,  officers' and  directors' liability  insurance covering  the
Indemnified  Parties who are currently covered  (in their capacities as officers
and directors) by  P-B's existing officers'  and directors' liability  insurance
policies,  on  terms substantially  no less  advantageous  to such  officers and
directors than such existing insurance.

    BOARD OF DIRECTORS.  In the Merger Agreement, Nellcor has agreed to take all
action necessary to  cause Burton A.  Dole, Jr.  and Thomas A.  McDonnell to  be
appointed  to the Nellcor Board, effective as  of the Effective Time, for a term
expiring at the first annual meeting of Nellcor's stockholders after the Merger.
Mr. Dole is currently Chairman, President and Chief Executive Officer of P-B and

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<PAGE>
Mr. McDonnell is currently a director of P-B. In addition, Nellcor has agreed in
the Merger Agreement to  nominate Mr. Dole and  Mr. McDonnell for reelection  at
the  first annual meeting of Nellcor's stockholders following the Merger, and to
nominate for election as an additional director of Nellcor at such first  annual
meeting  a person selected  by Nellcor who  is not a  current or former officer,
director or employee of P-B  and who is mutually agreeable  to Mr. Dole and  Mr.
McDonnell.  See  "Management  of  Nellcor  After  the  Merger  --  Directors and
Executive Officers After the Merger."

    In the  Merger Agreement,  Nellcor has  agreed that  it will  guarantee  the
payment  of P-B's  obligations with  respect to  P-B's Directors Post-Retirement
Income Plan.

    RETENTION AND BONUS ARRANGEMENTS.  Pursuant to the Merger Agreement, Nellcor
has agreed to cause P-B to adopt immediately after consummation of the Merger, a
Retention Compensation Plan to be effective  from and after the consummation  of
the  Merger for  the benefit  of the  following senior  level employees  of P-B:
Messrs. Dole,  Morrow, Doyle,  Jones, Rankin,  Niles, Treff,  Stewart,  Stowell,
Gaskin,  Miller, Jonietz, Fettes,  Neal, Haan, Hope  and Ross. The  terms of the
Retention Compensation Plan  will provide for  payment of a  lump sum  retention
bonus  to each of  such individuals who  remains employed by  Nellcor or P-B 366
days after the Merger or if earlier  terminated without cause as defined in  the
Retention Compensation Plan.

    In  connection  with  the  Merger  Agreement,  P-B  amended  its  Management
Incentive Compensation Plan A and Plan B for Fiscal Year 1996 to provide that no
further benefits shall  be payable thereunder.  In lieu of  benefits under  such
plan,  Nellcor agreed to cause P-B  to adopt, immediately after the consummation
of the Merger, a Merger Incentive Compensation Plan effective from and after the
consummation of the Merger for the  benefit of employees of P-B that  previously
participated  in P-B's Management  Incentive Compensation Plan A  and Plan B for
Fiscal Year 1996. Participation in the Merger Incentive Compensation Plan  shall
be  available to the same officers and employees who were participating in P-B's
Management Incentive Compensation Plan A and Plan  B for Fiscal Year 1996 as  of
April  30, 1995 and  who remain actively employed  by P-B as  of the Merger. The
performance targets under the new plan shall be generally the same as under  the
predecessor  plan  except that  there will  be no  requirement that  P-B achieve
minimum earnings of  $2.00 per share.  Bonuses will be  prorated based upon  the
amount  of P-B's fiscal year that occurs prior to the Merger and will be paid to
employees that remain employed by  Nellcor or P-B on  February 1, 1996, or  that
are  earlier  terminated  without  cause  as  defined  in  the  Merger Incentive
Compensation Plan.

CERTAIN FEDERAL INCOME TAX CONSEQUENCES

    The anticipated  federal  income  tax  consequences of  the  Merger  are  as
follows:

        (i)  the Merger will  constitute a reorganization  within the meaning of
    Section 368(a) of the Code, and Nellcor, Sub and P-B will each be a party to
    that reorganization within the meaning of Section 368(b) of the Code;

        (ii) no gain or loss will be recognized by Nellcor or P-B as a result of
    the Merger;

       (iii) no gain or loss will be recognized by the stockholders of P-B  upon
    the conversion of their P-B Common Stock into shares of Nellcor Common Stock
    pursuant to the Merger except with respect to cash, if any, received in lieu
    of fractional shares of Nellcor Common Stock;

       (iv)  a  stockholder of  P-B will  recognize  gain or  loss equal  to the
    difference between the cash received in lieu of a fractional share  interest
    of  Nellcor Common Stock and such  stockholder's tax basis in the fractional
    share for which cash is received;

        (v) no gain or loss will  be recognized by the existing stockholders  of
    Nellcor as a result of the Merger;

       (vi)  the  aggregate tax  basis  of the  shares  of Nellcor  Common Stock
    received in exchange for shares of  P-B Common Stock pursuant to the  Merger
    (including fractional shares for which cash

                                       45
<PAGE>
    is  received) will be the same as the aggregate tax basis for such shares of
    P-B Common Stock, decreased by the amount of any tax basis allocable to  the
    fractional share interests for which cash is received; and

       (vii)  the holding period for shares  of Nellcor Common Stock received in
    exchange for shares of P-B Common Stock pursuant to the Merger will  include
    the  period that such  shares of P-B  Common Stock were  held by the holder,
    provided such shares of P-B Common Stock were held as capital assets by  the
    holder at the Effective Time.

    It  is a condition to the consummation of the Merger that Nellcor receive an
opinion from its counsel, Morrison &  Foerster, and that P-B receive an  opinion
from its counsel, Blackwell Sanders Matheny Weary & Lombardi L.C., substantially
to  the effect that the Merger will have the federal income tax consequences set
forth above. Such opinions will be based upon the Code, its legislative history,
existing and  proposed  regulations  thereunder,  published  rulings  and  court
decisions,  all as in effect on the Effective  Time and all of which are subject
to change, which  change could be  retroactive. In addition,  in rendering  such
opinions,  counsel will rely  upon representations contained  in certificates of
Nellcor, P-B and  others, and may  condition such opinions  on the receipt  from
those  stockholders of P-B holding a substantial amount of P-B Common Stock (the
"Major Stockholders") of  a certificate verifying  that such Major  Stockholders
have  no  plan  or intention  as  of the  Effective  Time to  sell,  exchange or
otherwise dispose of  the shares of  Nellcor Common Stock  to be distributed  to
them  in the Merger.  A ruling from  the United States  Internal Revenue Service
concerning the tax consequences of the Merger will not be requested.

    THE DISCUSSION SET FORTH ABOVE IS INCLUDED FOR GENERAL INFORMATION ONLY.  IT
DOES  NOT ADDRESS  THE STATE,  LOCAL OR  FOREIGN TAX  ASPECTS OF  THE MERGER. IN
ADDITION, IT DOES NOT DISCUSS THE FEDERAL INCOME TAX CONSIDERATIONS THAT MAY  BE
RELEVANT  TO CERTAIN PERSONS, INCLUDING HOLDERS  OF OPTIONS OR WARRANTS, AND MAY
NOT APPLY TO CERTAIN HOLDERS SUBJECT TO SPECIAL TAX RULES, INCLUDING HOLDERS WHO
ACQUIRED P-B COMMON STOCK PURSUANT TO THE EXERCISE OF EMPLOYEE STOCK OPTIONS  OR
RIGHTS  OR OTHERWISE RECEIVED SUCH STOCK  AS COMPENSATION, DEALERS IN SECURITIES
AND FOREIGN HOLDERS.

    EACH P-B STOCKHOLDER SHOULD CONSULT HIS OR HER OWN TAX ADVISOR WITH  RESPECT
TO  THE SPECIFIC  TAX CONSEQUENCES OF  THE MERGER  TO HIM OR  HER, INCLUDING THE
APPLICATION AND EFFECT OF STATE, LOCAL AND FOREIGN TAX LAWS.

ACCOUNTING TREATMENT

    The Merger is intended to qualify  as a pooling of interests for  accounting
and  financial reporting purposes. Under this method of accounting, the recorded
historical cost basis of the assets and  liabilities of Nellcor and P-B will  be
carried  forward to the  operations of the combined  companies at their recorded
amounts, results of operations of the combined companies will include income  of
Nellcor and P-B for the entire fiscal period in which the combination occurs and
the  historical results of operations of the separate companies for fiscal years
prior to the Merger will be combined  and reported as the results of  operations
of the combined companies.

    Consummation  of the Merger  is conditioned upon receipt  by each of Nellcor
and P-B of a letter from their respective independent public accountants stating
that, in their  respective opinions,  the Merger will  qualify as  a pooling  of
interests  for accounting  purposes. See  "The Merger  Agreement -- Conditions."
Certain events, including certain transactions with respect to P-B Common  Stock
or  Nellcor  Common Stock  by affiliates  of P-B  or Nellcor,  respectively, may
prevent the Merger from qualifying as a pooling of interests for accounting  and
financial reporting purposes. For information

                                       46
<PAGE>
concerning  certain restrictions to be imposed on the transferability of Nellcor
Common Stock  to be  received by  affiliates in  order, among  other things,  to
ensure  the availability of  pooling of interests  accounting treatment, see "--
Resale Restrictions."

REGULATORY APPROVALS

    Under the HSR Act, and the rules promulgated thereunder by the Federal Trade
Commission (the "FTC"),  the Merger  cannot be  consummated until  notifications
have  been given and certain  information has been furnished  to the FTC and the
Antitrust Division of the Department  of Justice (the "Antitrust Division")  and
specified  waiting period requirements have been satisfied. Nellcor and P-B each
filed notification and  report forms  under the  HSR Act  with the  FTC and  the
Antitrust Division on June 12, 1995.

    The waiting period under the HSR Act for Nellcor and P-B expired on June 26,
1995. Neither Nellcor nor P-B received a request for additional information from
the Antitrust Division or the FTC prior to expiration of the waiting period.

    At  any  time before  or  after consummation  of  the Merger,  the Antitrust
Division or the FTC, or  any state, could take  such action under the  antitrust
laws  as  it deems  necessary  or desirable  in  the public  interest, including
seeking to  enjoin the  consummation of  the Merger  or seeking  divestiture  of
substantial  assets of  Nellcor or  P-B. Private parties  may also  seek to take
legal action under the antitrust laws under certain circumstances. In  addition,
non-United  States  governmental and  regulatory  authorities may  seek  to take
action under  applicable  antitrust laws.  There  can  be no  assurance  that  a
challenge  to the Merger  will not be made  or, if such  challenge is made, that
Nellcor will prevail.

    Under the terms of the FDA consent decree applicable to P-B, P-B must notify
the  FDA  10  days  prior  to  consummation  of  the  Merger.  See   "Investment
Considerations -- Government Regulation."

    The  obligations of Nellcor and P-B to  consummate the Merger are subject to
the condition that  there be  no preliminary  or permanent  injunction or  other
order  by any  federal, state  or foreign  court of  competent jurisdiction that
prevents consummation  of  the Merger,  and  that  there be  no  statute,  rule,
regulation,   executive  order,  stay,  decree  or  judgment  by  any  court  or
governmental authority  that  prohibits or  restricts  the consummation  of  the
Merger.  See "The  Merger Agreement  -- Conditions."  Either Nellcor  or P-B may
terminate the Merger  Agreement if any  court of competent  jurisdiction in  the
United  States or  other United  States governmental  body shall  have issued an
order, decree or  ruling or  taken any  other action  restraining, enjoining  or
otherwise  prohibiting the  Merger and such  order, decree, ruling  or any other
action shall  have become  final  and non-appealable,  provided that  the  party
seeking  to terminate the Merger  Agreement for such reason  shall have used all
reasonable efforts  to remove  such order,  decree or  ruling. See  "The  Merger
Agreement -- Termination."

RESALE RESTRICTIONS

    All  shares  of Nellcor  Common Stock  received by  P-B stockholders  in the
Merger will be freely transferable, except  that shares of Nellcor Common  Stock
received  by persons who are deemed to  be "affiliates" (as such term is defined
under the Securities  Act) of P-B  may be  resold by them  only in  transactions
permitted  by the resale provisions of Rule 145 promulgated under the Securities
Act (or Rule 144 in the case  of such persons who become affiliates of  Nellcor)
or as otherwise permitted under the Securities Act. Persons who may be deemed to
be  affiliates of P-B or Nellcor  generally include individuals or entities that
control, are controlled by, or are under common control with, such party and may
include certain  officers and  directors  of such  party  as well  as  principal
stockholders of such party.

    Commission  guidelines  regarding qualifying  for  the pooling  of interests
method of  accounting  also limit  sales  by  affiliates of  the  acquiring  and
acquired  companies in  a business  combination. Commission  guidelines indicate
further that the pooling of interests method of accounting generally will not be
challenged on the  basis of  sales by affiliates  of the  acquiring or  acquired
company if they do not

                                       47
<PAGE>
dispose  of any of the shares they own or shares they receive in connection with
a merger during the period beginning 30  days before the merger and ending  when
financial  results covering  at least 30  days of combined  operations have been
published. See "-- Accounting Treatment."

    The Merger Agreement requires each of Nellcor and P-B to use all  reasonable
efforts  to  cause  each  of  its  affiliates  to  execute  a  written agreement
restricting the disposition by such person of the shares of Nellcor Common Stock
to be received by such person in the Merger.

NO APPRAISAL RIGHTS

    UNDER THE  DGCL,  HOLDERS  OF  NELLCOR COMMON  STOCK  ARE  NOT  ENTITLED  TO
APPRAISAL  RIGHTS WITH RESPECT  TO THE MERGER  OR THE OTHER  MATTERS TO BE ACTED
UPON AT THE NELLCOR  SPECIAL MEETING, AND  HOLDERS OF P-B  COMMON STOCK ARE  NOT
ENTITLED TO APPRAISAL RIGHTS WITH RESPECT TO THE MERGER.

                                       48
<PAGE>
                              THE MERGER AGREEMENT

    THE  FOLLOWING  IS  A BRIEF  SUMMARY  OF  CERTAIN PROVISIONS  OF  THE MERGER
AGREEMENT, INCLUDING  THE AMENDMENT  THERETO, COPIES  OF WHICH  ARE ATTACHED  AS
ANNEXES  A  AND  B, RESPECTIVELY,  TO  THIS PROXY  STATEMENT/PROSPECTUS  AND ARE
INCORPORATED HEREIN BY REFERENCE. THIS SUMMARY  IS QUALIFIED IN ITS ENTIRETY  BY
REFERENCE  TO THE  FULL TEXT  OF THE  MERGER AGREEMENT,  INCLUDING THE AMENDMENT
THERETO.

THE MERGER

    Pursuant to the Merger  Agreement, and subject to  the terms and  conditions
thereof,  at the Effective Time, Sub will be  merged with and into P-B, with P-B
as the Surviving Corporation. The Merger will have the effects specified in  the
DGCL.

    P-B's  Restated  Certificate  of  Incorporation,  amended  and  restated  as
referred to  in  the Merger  Agreement,  shall be  the  Surviving  Corporation's
Certificate  of Incorporation. Sub's Bylaws shall be the Surviving Corporation's
Bylaws. The directors  of Sub shall  be the initial  directors of the  Surviving
Corporation,  and  the officers  of P-B  shall  be the  initial officers  of the
Surviving Corporation.

EFFECTIVE TIME OF THE MERGER

    The closing of the  transactions contemplated by  the Merger Agreement  (the
"Closing") shall take place on the first business day (the "Closing Date") after
the  later  of (i)  the date  on  which both  P-B's and  Nellcor's stockholders'
meetings approving the Merger shall have occurred, and (ii) the day on which all
of the conditions to the Merger are  satisfied or waived, or at such other  date
as Nellcor and P-B shall agree. See "-- Conditions."

    As  soon as practicable after  the Closing, a Certificate  of Merger will be
filed with  the Secretary  of State  of the  State of  Delaware as  provided  in
Section  251 of the  DGCL (the "Certificate  of Merger"). The  time at which the
Certificate of Merger is so filed is referred to as the Effective Time.

CONVERSION OF SECURITIES

    As a result of the Merger and without any action on the part of the  holders
thereof, each share of P-B Common Stock issued and outstanding immediately prior
to  the Effective Time,  together with the associated  P-B Common Stock Purchase
Right, will be  converted into the  right to receive  0.88 of a  fully paid  and
nonassessable  share (the  "Exchange Ratio")  of Nellcor  Common Stock, together
with the  corresponding  percentage of  an  associated Nellcor  Preferred  Stock
Purchase  Right,  and will  cease to  be  outstanding and  will be  canceled and
retired, except as described  below. Each holder  of a certificate  representing
any  such shares of P-B Common Stock  (a "Certificate") will thereafter cease to
have any rights  with respect  to such  P-B Common  Stock, except  the right  to
receive,  without interest, shares of  Nellcor Common Stock and  cash in lieu of
fractional shares (as described in "--  Exchange of Shares") upon the  surrender
of  such Certificate.  If prior  to the Effective  Time Nellcor  should split or
combine the shares of  Nellcor Common Stock,  or pay a  stock dividend or  other
stock  distribution in, or  in exchange of,  shares of Nellcor  Common Stock, or
engage in any similar transaction, then the Exchange Ratio will be appropriately
adjusted to  reflect  such  split,  combination,  dividend,  exchange  or  other
distribution or similar transaction.

    Each  share of P-B Common Stock held in P-B's treasury at the Effective Time
will cease to be outstanding and will be canceled and retired without payment of
any consideration therefor. All shares of  Nellcor Common Stock owned by P-B  or
any subsidiary of P-B shall become treasury stock of Nellcor.

STOCK OPTIONS

    As  of the Effective Time,  each of the options  to acquire P-B Common Stock
(each a "P-B Stock Option") outstanding as  of the date of the Merger  Agreement
will be converted into an option (or a new substitute option shall be issued) to
purchase the number of shares of Nellcor Common Stock (rounded up to the nearest
whole  share) equal to the number of shares  of P-B Common Stock subject to such
option multiplied  by the  Exchange Ratio,  at an  exercise price  per share  of
Nellcor  Common Stock (rounded  down to the  nearest penny) equal  to the former
exercise price per share of P-B

                                       49
<PAGE>
Common Stock under such option immediately  prior to the Effective Time  divided
by  the Exchange  Ratio; provided that  in the case  of any P-B  Stock Option to
which Section  421 of  the Code  applies by  reason of  its qualification  under
Section 422 of the Code, the conversion formula shall be adjusted, if necessary,
to  comply  with Section  424(a)  of the  Code.  Except as  provided  above, the
converted or substituted P-B  Stock Options shall be  subject to the same  terms
and  conditions as were applicable to P-B Stock Options immediately prior to the
Effective Time.

    As of the Effective Time, Nellcor  will issue an option intended to  qualify
as  an incentive stock  option in substitution for  each incentive stock option,
and will issue a non-qualified stock  option in substitution for each P-B  Stock
Option  that is a non-qualified stock option,  in each case which (i) was issued
under P-B's 1988  Stock Benefit Plan,  (ii) had its  vesting and  exercisability
accelerated  as a result of the Merger,  and (iii) expired unexercised as of the
Effective Time. The  number of shares  of Nellcor Common  Stock subject to  such
substituted  options, and  the exercise price  per share of  such Nellcor Common
Stock, shall be  based upon the  number of shares  of P-B Common  Stock and  the
exercise  price per  share of P-B  Common Stock  under the terms  of the expired
option, in each case as provided in the preceding paragraph. To the extent  that
any  P-B  Stock  Options under  P-B's  1979  Employee Stock  Benefit  Plan would
terminate as of  the Effective  Time as  a result  of the  Merger, Nellcor  will
substitute  equivalent options to acquire Nellcor Common Stock on the same basis
as described above with respect to options under P-B's 1988 Stock Benefit  Plan.
Subject  to the foregoing, all substituted options under this paragraph shall be
subject to the same terms and conditions  as were applicable to the expired  P-B
Stock  Options for which  they are substituted, except  that the acceleration of
vesting and exercisability as a result of the Merger shall not be given effect.

    Within fifteen (15) days after the Effective Time, Nellcor will cause to  be
filed  one or more registration statements on Form S-8 under the Securities Act,
or amendments to its existing registration statements on Form S-8 or  amendments
to  such other registration statements as may be available, in order to register
the shares  of Nellcor  Common Stock  issuable upon  exercise of  the  aforesaid
converted P-B Stock Options. The consummation of the Merger shall not be treated
as a termination of employment for purposes of the Option Plans.

EXCHANGE OF SHARES

    As  soon as  reasonably practicable after  the Effective  Time, the Exchange
Agent will mail to  each holder of record  of P-B Common Stock  (i) a letter  of
transmittal  and (ii)  instructions for  use in  effecting the  surrender of the
Certificates in exchange for certificates representing shares of Nellcor  Common
Stock.  Upon surrender of a Certificate to the Exchange Agent together with such
letter of transmittal, duly  executed, the holder of  such Certificate shall  be
entitled  to receive  in exchange therefor  (i) a  certificate representing that
number of whole shares of Nellcor Common Stock and (ii) a check representing the
amount of cash in lieu of fractional  shares, if any, which such holder has  the
right  to receive in respect of the Certificate so surrendered. P-B STOCKHOLDERS
SHOULD  NOT  SEND  IN  THEIR  CERTIFICATES  UNTIL  THEY  RECEIVE  A  LETTER   OF
TRANSMITTAL.

    No fractional shares of Nellcor Common Stock shall be issued pursuant to the
Merger. In lieu thereof, cash adjustments will be paid in an amount equal to the
product  of the fraction of a share of Nellcor Common Stock that would otherwise
be issuable multiplied by  the closing sales price  per share of Nellcor  Common
Stock on Nasdaq on the business day immediately preceding the Closing Date.

    No  dividends on  shares of  Nellcor Common  Stock will  be paid  to persons
entitled to receive  certificates representing  shares of  Nellcor Common  Stock
until  such  persons surrender  their Certificates.  Upon such  surrender, there
shall be paid  to the person  in whose name  the certificates representing  such
shares  of Nellcor Common Stock shall be  issued, any dividends which shall have
become payable with respect to such  shares of Nellcor Common Stock between  the
Effective  Time and  the time of  such surrender.  In no event  shall the person
entitled to  receive such  dividends be  entitled to  receive interest  on  such
dividends.

                                       50
<PAGE>
    If any certificates for shares of Nellcor Common Stock are to be issued in a
name  other than that in which  the Certificate surrendered in exchange therefor
is registered,  it  shall  be a  condition  of  such exchange  that  the  person
requesting  such exchange (i)  pay to the  Exchange Agent any  transfer or other
taxes required by reason thereof, or (ii) establish that such tax has been  paid
or is not applicable.

    At  the Effective Time, the stock transfer  books of P-B shall be closed and
no transfer of shares of P-B Common Stock shall thereafter be made.

    Neither the Exchange Agent  nor any party to  the Merger Agreement shall  be
liable  to a  holder of  shares of P-B  Common Stock  for any  shares of Nellcor
Common Stock or dividends thereon or  the cash payment for fractional  interests
delivered to a public official pursuant to applicable escheat laws.

    In the event that any Certificate shall have been lost, stolen or destroyed,
upon  (i) the making  of an affidavit of  that fact by  the person claiming such
Certificate to be lost, stolen or destroyed, and (ii) if required by Nellcor, in
its discretion, the posting by such person of a bond in such sum as Nellcor  may
direct  as indemnity, or  such other form  of indemnity, as  Nellcor may direct,
against any  claim  that  may be  made  against  Nellcor with  respect  to  such
Certificate,  Nellcor will  issue or  cause to  be issued  in exchange  for such
Certificate the number of whole shares of Nellcor Common Stock and cash in  lieu
of  fractional shares into which  the shares of P-B  Common Stock represented by
the Certificate are converted in the Merger.

REPRESENTATIONS AND WARRANTIES

    The Merger  Agreement contains  certain  representations and  warranties  by
Nellcor and Sub, on the one hand, and P-B, on the other hand, relating to, among
other  things, (a) due  organization, power and  standing; (b) capital structure
and ownership of  subsidiaries; (c) the  authorization, execution, delivery  and
enforceability  of the Merger Agreement; (d) required consents and approvals and
the absence  of breaches  or  violations of  certificates of  incorporation  and
by-laws, agreements and instruments, and law; (e) the filing of required reports
with  the  Commission;  (f)  the  absence  of  certain  changes  or  events; (g)
information in  this Proxy  Statement/Prospectus;  (h) litigation;  (i)  certain
contracts  and agreements (including contracts  with physicians, hospitals, HMOs
and  third  party  providers);  (j)  employee  benefit  plans;  (k)  taxes;  (l)
compliance  with applicable law; (m) labor and employment matters; (n) ownership
of shares of the  other's stock; (o) insurance;  (p) environmental matters;  (q)
intellectual  property rights; (r) dealings with  the FDA and other governmental
entities concerned with medical products  sold by Nellcor or P-B,  respectively;
(s)  real property;  (t) the  effect of  the Merger  on their  respective Rights
Agreements; (u) ownership of their shares; and (v) receipt of fairness opinions.

CERTAIN COVENANTS

    Nellcor and P-B have agreed that, prior to the Effective Time, except as set
forth in their respective Disclosure Schedules, among other things: (i) each  of
their  respective businesses shall  be conducted only in  the ordinary and usual
course of business, consistent with past  practices; and (ii) each of them  will
use  its  best efforts  to preserve  intact its  business organization,  to keep
available the services  of its and  its subsidiaries' present  officers and  key
employees,  and to preserve the goodwill  of those having business relationships
with it and its subsidiaries. Nellcor and P-B also have agreed that, among other
things: (i)  through the  Effective Time,  they  will confer  on a  regular  and
frequent  basis, and  each will report  to the  other the general  status of its
ongoing operations, deliver to the  other unaudited consolidated balance  sheets
and  related consolidated statements  of income, changes  in stockholders equity
and changes in financial position and promptly notify the other of any  material
change  in the  normal course  of its  business or  in its  or its subsidiaries'
properties; (ii) each will use all  reasonable efforts to cause to be  delivered
to  the other  a letter  from its independent  auditors, in  scope and substance
consistent with  applicable  professional  standards for  letters  delivered  by
independent  public  accountants  in  connection  with  registration  statements
similar to  the Registration  Statement  and, if  requested  by the  other,  use
reasonable  efforts to cause to  be delivered to the  other an update, dated the
Closing Date, of such letter; (iii) each will report to the other on operational
matters and promptly advise the other of  any change or event having, or  which,
insofar as can reasonably be

                                       51
<PAGE>
foreseen, could have, a material adverse effect on the business, assets, results
of  operation or  financial condition  of it  and its  subsidiaries, taken  as a
whole, or  which would  cause or  constitute a  material breach  of any  of  the
representations,   warranties  or  covenants  of  it  contained  in  the  Merger
Agreement; (iv) each will file all reports  required to be filed by it with  the
Commission and deliver to the other copies of all such reports; (v) except where
prohibited  by applicable statutes  and regulations, each  will promptly provide
the other with copies of all other filings made by such party with any state  or
federal  government  entity  in  connection with  the  Merger  Agreement  or the
transactions contemplated thereby; and (vi) through the Effective Time, each and
its respective subsidiaries will afford to the other access to all of its books,
records, properties, facilities, personnel commitments and records and each will
furnish to the  other all  information concerning its  business, properties  and
personnel as such other party may reasonably request.

   
    Each  of  Nellcor and  P-B has  agreed  that, prior  to the  Effective Time,
neither it nor any  of its subsidiaries  will, among other  things: (i) sell  or
pledge  or  agree  to sell  or  pledge  any stock  owned  by  it in  any  of its
subsidiaries; (ii) amend its Restated  Certificate of Incorporation or  By-Laws;
(iii)  split, combine or reclassify any  shares of its outstanding capital stock
or declare, set aside or pay any dividend or other distribution payable in cash,
stock or  property in  respect of  its  capital stock,  or redeem,  purchase  or
otherwise  acquire any shares of its capital stock or other securities or shares
of the capital stock or other securities of any of its subsidiaries, other  than
(a)  in connection with the  use of shares of capital  stock to pay the exercise
price or tax withholdings  in connection with  its stock-based employee  benefit
plans  in the ordinary course  of business in accordance  with past practice and
(b) P-B's  $0.03 per  share regular  cash dividend  declared in  May 1995;  (iv)
authorize  for issuance, issue,  sell, pledge, dispose  of, encumber, deliver or
agree or commit to issue, sell, pledge, or deliver any additional shares of,  or
rights  of any kind to acquire any shares  of, its capital stock of any class or
exchangeable into shares of stock of any class or any Voting Debt (as defined in
the Merger Agreement), except for unissued shares of Nellcor Common Stock or P-B
Common Stock, as the case may be, reserved for issuance upon the exercise of the
stock options  or warrants  pursuant to  Nellcor's employee  and director  stock
plans  or P-B's employee stock plans;  (v) acquire, dispose of, transfer, lease,
license, mortgage, pledge  or encumber any  material assets, other  than in  the
ordinary  course of  business and  consistent with  past practices;  (vi) incur,
assume or prepay  any material indebtedness  or other liabilities  or issue  any
debt  securities, other than  in the ordinary course  of business and consistent
with past practices; (vii) assume, guarantee, endorse or otherwise become liable
or responsible for the obligations of any other person (other than a subsidiary)
in a  material  amount,  other than  in  the  ordinary course  of  business  and
consistent  with past  practices; (viii)  make any  material loans,  advances or
capital contributions to,  or investments in,  any other person  (other than  to
subsidiaries), other than in the ordinary course of business and consistent with
past  practices; (ix) fail  to maintain adequate  insurance consistent with past
practices for their businesses and properties;  or (x) enter into any  contract,
agreement,  commitment  or  arrangement  with  respect  to  any  of  the matters
described in clauses (iv)-(ix).
    

    Nellcor and P-B have agreed that neither of them will change its (i) methods
of accounting in  effect at,  with respect  to Nellcor,  July 3,  1994 or,  with
respect to P-B, January 31, 1995, except as contemplated by the Merger Agreement
or  as  required  by  changes in  generally  accepted  accounting  principles as
concurred in by such party's independent auditors, or (ii) fiscal year.

    Nellcor and  P-B have  agreed that  neither P-B,  Nellcor nor  any of  their
respective  subsidiaries shall  (i) knowingly  take, or  allow to  be taken, any
action which  would jeopardize  the treatment  of  the Merger  as a  pooling  of
interests  for accounting purposes or (ii) knowingly  take, or allow to be taken
or fail  to take  any  action, which  act or  failure  to act  would  jeopardize
qualification  of the Merger  as a reorganization within  the meaning of Section
368(a) of the Code.

    P-B and Nellcor have  agreed that, until the  Effective Time, Sub shall  not
engage  in any activities of any nature except as provided in or contemplated by
the Merger Agreement.

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<PAGE>
    P-B and Nellcor have agreed that each will, and will cause its  subsidiaries
to,  use all  reasonable efforts  (i) (a)  to take,  or cause  to be  taken, all
actions necessary to comply  promptly with all legal  requirements which may  be
imposed  on such party  or its subsidiaries  with respect to  the Merger and the
consummation of the transactions contemplated  by the Merger Agreement,  subject
to  the appropriate vote  or consent of  stockholders and (b)  to obtain (and to
cooperate with the other party to  obtain) any consent, authorization, order  or
approval of, or any exemption by, any governmental entity or any other public or
private  third party which is  required to be obtained or  made by such party or
any of  its subsidiaries  in connection  with the  Merger and  the  transactions
contemplated by the Merger Agreement; provided that neither P-B nor Nellcor will
be  obligated to take any action that would, in such party's reasonable opinion,
be materially burdensome to such party or  impact in such a manner the  economic
or  business benefits of the transactions  contemplated by the Merger Agreement,
or would result in the  imposition of a condition  or restriction that would  so
impact   such  benefits,  in  either  case  so  as  to  render  inadvisable  the
consummation of the Merger and (ii) not to take or omit to take any action,  and
not  to agree to take or omit to take  any action, the effect of which action or
omission would be to make any representation  or warranty of P-B or Nellcor,  as
applicable, in the Merger Agreement untrue or incorrect in any material respect.

    Nellcor  and P-B  have agreed that  Nellcor shall use  reasonable efforts to
take any action required to be taken under state securities or blue sky laws  in
connection  with the issuance of the shares  of Nellcor Common Stock pursuant to
the Merger Agreement,  and that P-B  will furnish Nellcor  with all  information
concerning  P-B and the holders of its  capital stock and take such other action
as Nellcor may reasonably request in connection with the Registration  Statement
and such issuance of shares of Nellcor Common Stock.

    Nellcor  and  P-B have  agreed  to, except  to  the extent  required  in the
exercise of the fiduciary duties of the Board of Directors of Nellcor or P-B, as
the case  may  be, under  applicable  law  as advised  by  independent  counsel,
recommend  approval and  adoption of  the Merger  Agreement by  their respective
stockholders and to use their respective  best efforts to obtain such  approval.
Nellcor  has  agreed to  vote or  cause to  be  voted in  favor of  approval and
adoption of the Merger Agreement  at the P-B Special  Meeting all shares of  P-B
Common  Stock which it beneficially owns at such time, although Nellcor does not
presently beneficially  own any  such shares.  Whenever any  event occurs  which
should  be set forth in  an amendment or a supplement  to the Proxy Statement or
any filing required  to be made  with the Commission,  each party will  promptly
inform the other and will cooperate in filing with the Commission and/or mailing
to stockholders such amendment or supplement.

    Nellcor  has agreed to notify Nasdaq of the listing of the shares of Nellcor
Common Stock to be issued pursuant to the Merger.

COMPENSATION PLANS

    Each of P-B and Nellcor has agreed  as to itself and its subsidiaries  that,
until  the Effective Time, it will not, without the prior written consent of the
other (except as required by applicable law or pursuant to existing  contractual
arrangements or solely to the extent necessary to make compensation increases in
the ordinary course of business consistent with past practices or make available
existing  benefit  arrangements to  new or  promoted  employees in  the ordinary
course of business in accordance with  past practice): (i) enter into, adopt  or
amend   any  bonus,   profit  sharing,  compensation,   stock  option,  pension,
retirement, deferred  compensation,  employment,  severance  or  other  employee
benefit  plan, agreement, trust, plan, fund  or other arrangement between P-B or
Nellcor, as applicable, and one or more of its officers, directors or  employees
(collectively,  "Compensation Plans"), in each case so as to materially increase
benefits thereunder, (ii) grant or become obligated to grant any increase in the
compensation or  fringe benefits  of  directors, officers  or employees  or  any
increase  in  the compensation  payable  or to  become  payable to  any officer,
except, with  respect  to  employees  other  than  officers,  for  increases  in
compensation  in the ordinary course of  business consistent with past practice,
or enter  into  any  contract,  commitment  or arrangement  to  do  any  of  the
foregoing,  except for  normal increases  and non-stock  benefit changes  in the
ordinary course of business consistent with

                                       53
<PAGE>
past practice,  (iii) institute  any new  employee benefit,  welfare program  or
Compensation  Plan,  (iv) make  any  change in  any  Compensation Plan  or other
employee welfare or benefit arrangement or enter into any employment or  similar
agreement  or arrangement  with any  employee, or  (v) enter  into or  renew any
contract, agreement, commitment or arrangement providing for the payment to  any
director,  officer or  employee of compensation  or benefits  contingent, or the
terms of which  are materially  altered in favor  of such  individual, upon  the
occurrence of any of the transactions contemplated by the Merger Agreement.

NO SOLICITATION

    Nellcor  and P-B have  agreed that until  the earlier of  termination of the
Merger Agreement or consummation of the Merger, neither P-B nor Nellcor, nor any
of their respective subsidiaries,  will (i) initiate,  solicit or encourage,  or
take  any other action to facilitate any inquiries or the making of any proposal
with respect to, or (ii)  except to the extent required  in the exercise of  the
fiduciary  duties of the Board  of Directors of P-B or  Nellcor, as the case may
be, under applicable law as advised by independent counsel in connection with an
unsolicited proposal, engage or participate in negotiations concerning,  provide
any  nonpublic information or data to, or  have any discussions with, any person
other than a party to  the Merger Agreement or  its affiliates relating to,  any
(a)  acquisition, (b) tender offer (including a self-tender offer), (c) exchange
offer, (d) merger, (e) consolidation, (f) acquisition of beneficial ownership of
(or the right to vote securities representing)  10% or more of the total  voting
power  of such entity or any of  its subsidiaries, (g) dissolution, (h) business
combination, (i) purchase of all or any significant portion of the assets or any
division of (or any equity  interest in) such entity  or any subsidiary, or  (j)
similar  transaction other  than the  Merger (such  proposals, announcements, or
transactions being referred to as "Acquisition Proposals").

    P-B and Nellcor  have agreed  to notify the  other if  any such  Acquisition
Proposals  (including the  identity of  the persons  making such  proposals and,
subject to the fiduciary duties of the Board of Directors of P-B or Nellcor, the
terms of such proposals) are  received and furnish to  the other party hereto  a
copy of any written proposal.

CERTAIN EMPLOYEE BENEFIT PLAN MATTERS

    Nellcor  has  made  certain  representations to  P-B  regarding  its current
intention with respect to providing employee benefits after the Effective  Time.
Such representations are limited to Nellcor's present intentions and are subject
to  a number of limitations. To the extent the Nellcor employee benefit programs
provide medical or dental welfare benefits after the Closing Date, Nellcor  will
cause  all pre-existing condition exclusions and "actively-at-work" requirements
to be waived, and Nellcor will provide  that any expenses incurred on or  before
the  Closing Date shall be taken into account under the Nellcor employee benefit
programs for purposes of satisfying  the applicable deductible, coinsurance  and
maximum   out-of-pocket  provisions   for  such  employees   and  their  covered
dependents.

    P-B has confirmed to  Nellcor that (i) all  P-B Stock Options granted  under
the  1988 Stock Benefit  Plan that were not  fully vested as of  the date of the
Merger Agreement provide  for acceleration of  exercisability effective 30  days
prior  to the  Merger and  all restricted  stock awards  provide for accelerated
vesting upon consummation of  the Merger, (ii) all  P-B Stock Options under  the
1988  Stock Benefit Plan provide for  expiration upon consummation of the Merger
and (iii)  all P-B  Stock Options  under the  1979 Employee  Stock Benefit  Plan
provide  for carry over so as to  become options to acquire Nellcor Common Stock
after the Merger.

    P-B has confirmed that it has  amended its Change of Control Severance  Plan
so  that (i) none of the transactions  contemplated by the Merger Agreement will
constitute a  "Change  of  Control"  as  defined  therein,  and  (ii)  effective
immediately  prior  to  consummation  of  the  Merger,  such  Change  of Control
Severance Plan shall terminate and be of no further force and effect.

    P-B has agreed, except with respect to  the rabbi trust of the Restated  P-B
Deferred  Compensation Plan and  other trusts in  accordance with past practice,
not to  deposit  into any  trust  amounts in  respect  of any  employee  benefit
obligations.

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<PAGE>
    P-B  has confirmed that it has amended its Management Incentive Compensation
Plan A and Plan B for Fiscal Year 1996 to provide that no further benefits shall
be payable thereunder subject  to the consummation of  the Merger and that  such
plans shall terminate from and after the Merger. In lieu of the benefits payable
under  such  Plans  for Fiscal  Year  1996,  Nellcor shall  cause  P-B  to adopt
immediately  after  the   consummation  of  the   Merger,  a  Merger   Incentive
Compensation   Plan  for  the  benefit  of  employees  of  P-B  that  previously
participated in such Management Incentive Compensation Plans. See "Interests  of
Certain Persons in the Merger."

    Nellcor and P-B have agreed that, from and after the Effective Time, neither
of them shall take any action to amend or modify P-B's Directors Post-Retirement
Income  Plan, except that such  plan shall not be  available to new directors of
P-B appointed by Nellcor from and after  the Merger. P-B shall continue to  make
all  payments required to be made under such plan to each former director of P-B
entitled to benefits thereunder.  Neither P-B nor Nellcor  shall fund any  rabbi
trust  with  respect to  such  plan, provided  that  Nellcor will  guarantee the
payment by P-B of P-B's obligations  under such plan. See "Interests of  Certain
Persons in the Merger."

    Nellcor  has agreed to cause the  adoption immediately after consummation of
the Merger of a  Retention Compensation Plan for  the benefit of certain  senior
level employees of P-B. See "Interests of Certain Persons in the Merger."

DIRECTOR AND OFFICER INDEMNIFICATION

    Nellcor  and the Surviving  Corporation have agreed  that for acts occurring
prior to the Effective  Time, all rights to  indemnification and advancement  of
expenses   existing  in  favor  of  the  directors  and  officers  of  P-B  (the
"Indemnified Parties") under the provisions existing  on the date of the  Merger
Agreement   of   the  Restated   Certificate   of  Incorporation,   By-Laws  and
indemnification agreements of P-B shall survive the Effective Time. In addition,
Nellcor and  the Surviving  Corporation  have agreed  to indemnify  and  advance
expenses  to the  Indemnified Parties to  the full extent  required or permitted
under the  provisions existing  on the  date of  the Merger  Agreement of  P-B's
Restated Certificate of Incorporation and By-Laws and indemnification agreements
of P-B. See "Interests of Certain Persons in the Merger."

    For  a period of six years after  the Effective Time, Nellcor will maintain,
with respect to claims  arising from facts or  events which occurred before  the
Effective  Time,  officers'  and  directors'  liability  insurance  covering the
Indemnified Parties who were covered as of  the date of the Merger Agreement  by
P-B's  existing officers' and directors'  liability insurance policies, on terms
substantially no  less advantageous  to such  officers and  directors than  such
existing  insurance.  See "The  Merger --  Interests of  Certain Persons  in the
Merger."

P-B ACCRUALS AND RESERVES

    P-B has agreed that it will, prior  to the Closing Date, review and, to  the
extent  determined necessary  or advisable,  consistent with  generally accepted
accounting principles and the accounting rules, regulations and  interpretations
of  the  Commission and  its staff,  modify its  accrual, reserve  and provision
policies and practices  to (a)  reflect the Surviving  Corporation's plans  with
respect  to the  conduct of  P-B's business  following the  Merger and  (b) make
adequate provision  for the  costs and  expenses relating  thereto so  as to  be
applied consistently on a mutually satisfactory basis with those of Nellcor. P-B
shall  not  be  obligated to  take  any  such action  unless  and  until Nellcor
acknowledges that all  conditions to  its obligations to  consummate the  Merger
have been satisfied.

NAME CHANGE

    The Nellcor Board is obligated to take all action necessary to submit to the
stockholders  of  Nellcor  an  amendment to  Nellcor's  Restated  Certificate of
Incorporation to  change  Nellcor's corporate  name  at the  Effective  Time  or
promptly thereafter to Nellcor Puritan Bennett Incorporated. Such name change is
contained in the Nellcor Charter Amendment Proposal.

MANAGEMENT AFTER THE MERGER

    In  the Merger Agreement, Nellcor has agreed to take all action necessary to
cause Burton A. Dole, Jr. and Thomas A. McDonnell to be appointed to the Nellcor
Board, effective as  of the Effective  Time, for  a term expiring  at the  first
annual meeting of Nellcor's stockholders after the Merger. Mr. Dole is currently
Chairman,  President and  Chief Executive  Officer of  P-B and  Mr. McDonnell is
currently a  director of  P-B. In  addition, Nellcor  has agreed  in the  Merger
Agreement to nominate Mr. Dole and

                                       55
<PAGE>
Mr.   McDonnell  for  reelection  at  the  first  annual  meeting  of  Nellcor's
stockholders following the Merger, and to nominate for election as an additional
director of Nellcor at  such first annual meeting  a person selected by  Nellcor
who  is not a current or former officer,  director or employee of P-B and who is
mutually agreeable to Mr. Dole and Mr. McDonnell.

    Nellcor has agreed to offer to Mr. Dole employment as Chairman of the  Board
of Directors of the combined companies pursuant to certain terms and conditions.
As  Chairman, Mr.  Dole will  chair meetings  of the  Board of  Directors of the
combined companies, the agenda for and the  conduct of which will be set by  the
President  and Chief Executive Officer of the combined companies. P-B has agreed
that it will  terminate the employment  of Mr. Dole  effective at the  Effective
Time  and obtain from Mr. Dole  an agreement modifying certain employee benefits
effective as of  the Effective  Time. In  connection with  such termination  and
modification,  the  Surviving Corporation  shall be  bound by  the terms  of the
employment agreement between Mr. Dole and P-B pursuant to which it shall pay  to
him certain severance amounts specified therein. See "The Merger -- Interests of
Certain Persons in the Merger."

    Nellcor  has agreed to offer to John  H. Morrow employment as Executive Vice
President of the  combined companies  and President of  the combined  companies'
Home  Health Care  Business pursuant  to certain  terms and  conditions. P-B has
agreed that it will obtain from Mr. Morrow agreements (i) canceling his existing
employment agreement effective at the Effective Time and (ii) modifying  certain
employee  benefits  effective  as of  the  Effective  Time. See  "The  Merger --
Interests of Certain Persons in the Merger."

CONDITIONS

    The respective obligations of each of  Nellcor and P-B to effect the  Merger
are  subject to  the satisfaction or  waiver of the  following conditions, among
others: (i) the  waiting period  applicable to  the consummation  of the  Merger
under  the HSR Act shall have expired  or been terminated; (ii) the Registration
Statement shall be effective in accordance with the provisions of the Securities
Act, and no  action, suit,  proceedings or  investigation by  the Commission  to
suspend  the effectiveness thereof shall have  been initiated and be continuing;
(iii) all necessary approvals under state securities and blue sky laws  relating
to  the  issuance  or  trading of  the  Nellcor  Common Stock  to  be  issued in
connection with the Merger shall have  been received; (iv) the Merger  Agreement
and  the transactions contemplated thereby shall  have been approved and adopted
by the stockholders of Nellcor and P-B; (v) no injunction or other order by  any
court  of competent jurisdiction which prohibits  the consummation of the Merger
shall have been issued and remain in  effect; (vi) other than the filing of  the
Certificate  of Merger, all authorizations, consents, orders or approvals of, or
declarations or filings with, and all expirations of waiting periods imposed by,
any governmental entity (all of  the foregoing, "Consents") which are  necessary
for  the consummation  of the  Merger, shall have  been filed,  occurred or been
obtained (all such permits, approvals, filings and consents and the lapse of all
such waiting periods being referred to as the "Requisite Regulatory  Approvals")
and  be in full force and effect; (vii)  there shall not be any action taken, or
any statute,  rule, regulation  or order  enacted, entered,  enforced or  deemed
applicable  to the Merger, by any federal or state governmental entity which, in
connection with  the  grant of  a  Requisite Regulatory  Approval,  imposes  any
condition or restriction upon the Surviving Corporation or its subsidiaries (or,
in  the  case of  any disposition  of  assets required  in connection  with such
Requisite Regulatory Approval, upon  Nellcor or its subsidiaries  or P-B or  its
subsidiaries)  which in any such  case would so impact  the economic or business
benefits of the transactions contemplated by  the Merger Agreement as to  render
inadvisable  the consummation  of the Merger;  and (viii) Nellcor  and P-B shall
have received (a) a  letter, dated the Closing  Date, addressed to Nellcor  from
Price  Waterhouse LLP,  Nellcor's independent  accountants ("Price Waterhouse"),
and (b) a letter, dated  the Closing Date, addressed to  P-B from Ernst &  Young
LLP, P-B's independent accountants ("Ernst & Young"), in each case to the effect
that  the  Merger qualifies  for pooling  of  interests treatment  for financial
reporting purposes  and that  such accounting  treatment is  in accordance  with
generally  accepted  accounting  principles,  and  Price  Waterhouse  shall have
received from Ernst & Young a letter stating that Ernst & Young is not aware  of
any  fact concerning P-B  or any of  its affiliates that  would preclude Nellcor
from accounting for the Merger by the pooling of interests method for  financial
reporting purposes.

    The  obligation of  each of  Nellcor and  P-B to  effect the  Merger is also
subject to the satisfaction of the following additional conditions, among  other
things:    (i)    the    other    party   shall    have    performed    in   all

                                       56
<PAGE>
material respects  its obligations  under the  Merger Agreement  required to  be
performed  by it at or  prior to the Effective  Time and the representations and
warranties of the other  party contained in the  Merger Agreement shall be  true
and  correct in all material respects at and as of the Effective Time as if made
at and as of  such time, except  as contemplated by  the Merger Agreement;  (ii)
each  shall have received an opinion of its counsel, substantially to the effect
that  the  Merger  will  be  treated  for  federal  income  tax  purposes  as  a
reorganization within the meaning of Section 368(a) of the Code and that Nellcor
and P-B will each be a party to the reorganization within the meaning of Section
368(b) of the Code; (iii) each of Nellcor and P-B shall have received an opinion
of  counsel to the other; (iv) each  shall have obtained the consent or approval
of each person whose  consent or approval shall  be required in connection  with
the  transactions contemplated  by the Merger  Agreement under  any agreement or
instrument; and (v) there shall not have occurred prior to the Closing Date  any
change,  or  any event  involving  a prospective  change,  in the  other party's
business, assets, financial condition or results of operation which has had,  or
is reasonably likely to have, in the aggregate a material adverse effect on such
other  party and its  subsidiaries taken as a  whole (other than  as a result of
changes or proposed changes  in federal or state  health care (including  health
care   reimbursement)   laws  or   regulations   of  general   applicability  or
interpretations thereof, changes in generally accepted accounting principles and
changes that could, under the circumstances, reasonably have been anticipated in
light of disclosures made in writing by  the other party prior to the  execution
of the Merger Agreement).

TERMINATION

    The  Merger Agreement may be terminated and the Merger abandoned at any time
prior  to  the  Effective  Time,  whether  before  or  after  approval  by   the
stockholders  of P-B or Nellcor:  (i) by mutual written  consent of Nellcor, Sub
and P-B; (ii) by either Nellcor and Sub,  on the one hand, or P-B, on the  other
hand,  if the Merger shall  not have been consummated  on or before December 31,
1995; (iii) by either  Nellcor and Sub, on  the one hand, or  P-B, on the  other
hand,  if there  shall have  been any  material breach  of a  representation and
warranty or material obligation of the other under the Merger Agreement and,  if
such breach is curable, such default shall have not been remedied within 10 days
(subject  to certain extensions) after receipt by  such other party of notice in
writing from  such  party specifying  such  breach  and requesting  that  it  be
remedied;  (iv) by either  of Nellcor or P-B,  if the Board  of Directors of the
other shall  have (a)  withdrawn or  modified in  a manner  adverse to  it  such
Board's  approval or recommendation  (or failed to  make such recommendation) of
the Merger Agreement  or the Merger,  or shall have  resolved to do  any of  the
foregoing, or (b) recommended an Acquisition Proposal other than the Merger; (v)
by  either Nellcor or P-B  if any court of  competent jurisdiction in the United
States or other  United States  governmental body  shall have  issued an  order,
decree  or ruling or taken any  other action restraining, enjoining or otherwise
prohibiting the Merger and such order, decree, ruling or any other action  shall
have  become final and non-appealable; (vi) by  either of Nellcor or P-B, if any
approval of the stockholders of the  other required for the consummation of  the
Merger  submitted for  approval shall  not have been  obtained by  reason of the
failure to obtain the required vote at a duly held meeting of stockholders or at
any adjournment thereof; or (vii) by either  of Nellcor or P-B, if its Board  of
Directors, in the exercise of its good faith judgment as to its fiduciary duties
to  its stockholders  under applicable  law as  advised by  independent counsel,
determines that such termination  is required by  reason of another  Acquisition
Proposal being made with respect to it.

    In  the event of termination, the Merger Agreement shall forthwith become of
no further effect and,  except for a  termination resulting from  a breach by  a
party  of the Merger Agreement, there shall be no liability or obligation on the
part of either Nellcor,  Sub or P-B or  their respective officers or  directors,
except as specifically provided in the Merger Agreement.

CANCELLATION FEES; EXPENSES

    If  at any time (i) P-B shall have entered into an agreement with respect to
an Acquisition Proposal, other than the Merger; (ii) P-B shall breach any of the
provisions of the Merger  Agreement relating to  Acquisition Proposals or  shall
recommend  or approve  an Acquisition Proposal  pursuant to  such provisions; or
(iii) any person, entity or group of persons or entities acting in concert shall
acquire beneficial ownership  of more  than fifty  percent (50%)  of the  voting
securities of P-B as a result of an Acquisition Proposal and, in the case of (i)
or (ii), the Merger Agreement is terminated by Nellcor pursuant to clause (iii),
(iv),  (vi) or  (vii) of the  first paragraph under  "Termination," then Nellcor
shall be entitled to be paid by P-B a fee in cash or immediately available funds
of ten  million U.S.  dollars ($10,000,000)  (the "P-B  Cancellation Fee").  The
payment of the P-B Cancellation Fee shall be

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<PAGE>
conditioned  on there being no material breach of the obligations of Nellcor and
Sub under  the Merger  Agreement.  Payment of  the  P-B Cancellation  Fee  shall
constitute  full settlement  of any and  all liabilities and  obligations of P-B
under the  Merger  Agreement,  except  for liabilities  arising  from  fraud  or
intentional  misrepresentation with respect  to the Merger  Agreement by P-B and
except as provided in the following paragraph.

    In the event that either P-B  or Nellcor terminates this Agreement  pursuant
to   clause  (iii)  of  the  first   paragraph  under  "Termination,"  then  the
nonterminating party shall pay to the terminating party two million U.S. dollars
($2,000,000) representing  full payment  of the  terminating party's  reasonable
out-of-pocket  expenses incurred  in connection with  the negotiation, execution
and performance of  this Agreement ("Expense  Reimbursement Payment");  provided
that  the terminating party  shall not be entitled  to any Expense Reimbursement
Payment if at the time of  termination the nonterminating party also would  have
been  entitled to  terminate this  Agreement pursuant  to such  clause (iii). In
addition, if the stockholders of Nellcor or  P-B fail to approve the Merger  and
this  Agreement is terminated  by P-B or  Nellcor pursuant to  clause (vi) under
"Termination," then the party whose stockholders  have so failed to approve  the
Merger  shall pay to the other party the Expense Reimbursement Payment; provided
that no such Expense Reimbursement Payment  shall be due under this sentence  if
the  stockholders of the party which would  have otherwise been entitled to such
Expense Reimbursement Payment have  previously failed to  approve the Merger  at
the stockholders meeting called for that purpose.

    If at any time (i) Nellcor shall have entered into an agreement with respect
to an Acquisition Proposal, other than the Merger; (ii) Nellcor shall breach any
of  the provisions of the Merger  Agreement relating to Acquisition Proposals or
shall recommend or approve an Acquisition Proposal pursuant to such  provisions;
or  (iii) any entity, person  or group of persons  or entities acting in concert
shall acquire  beneficial ownership  of more  than fifty  percent (50%)  of  the
voting securities of Nellcor as a result of an Acquisition Proposal, and, in the
case  of (i)  or (ii), this  Agreement is  terminated by P-B  pursuant to clause
(iii), (iv), (vi) or (vii) of the first paragraph under "Termination," then  P-B
shall  be entitled to be paid by Nellcor  a fee in cash or immediately available
funds of  ten  million U.S.  dollars  ($10,000,000) (the  "Nellcor  Cancellation
Fee"). The payment of the Nellcor Cancellation Fee shall be conditioned on there
being  no material breach of the obligations  of P-B under the Merger Agreement.
Payment of the Nellcor Cancellation Fee shall constitute full settlement of  any
and  all  liabilities and  obligations of  Nellcor  under the  Merger Agreement,
except for liabilities arising from fraud or intentional misrepresentation  with
respect  to  the Merger  Agreement  by Nellcor  and  except as  provided  in the
preceding paragraph.

AMENDMENT; WAIVER

    The Merger Agreement may be amended by action taken by Nellcor, Sub and  P-B
at  any time  before or after  approval thereof  by the stockholders  of P-B and
Nellcor, but, after any such approval,  no amendment shall be made which  alters
the  Exchange Ratio or which in any  way materially adversely affects the rights
of such stockholders,  without the  further approval of  such stockholders.  The
Merger Agreement may not be amended except by an instrument in writing signed on
behalf of each of the parties hereto.

    At any time prior to the Effective Time, Nellcor, Sub and P-B hereto may (i)
extend  the time for the performance of any  of the obligations or other acts of
the other parties to  the Merger Agreement, (ii)  waive any inaccuracies in  the
representations  and  warranties contained  in the  Merger  Agreement or  in any
document delivered pursuant to the Merger Agreement, and (iii) waive  compliance
with any of the agreements or conditions contained in the Merger Agreement.

EXPENSES

    Except  as provided in the Merger Agreement, all costs and expenses incurred
in connection  with  the  Merger Agreement  and  the  transactions  contemplated
thereby  (whether or not the  Merger is consummated) shall  be paid by the party
incurring such expenses, except  that if the Merger  is not consummated  Nellcor
and  P-B shall  share equally the  expenses incurred in  connection with filings
under the HSR Act, printing and mailing this Proxy Statement/Prospectus and  all
aspects of the Registration Statement.

                                       58
<PAGE>
                     MANAGEMENT OF NELLCOR AFTER THE MERGER

DIRECTORS AND EXECUTIVE OFFICERS AFTER THE MERGER

    In  the Merger Agreement, Nellcor has agreed to take all action necessary to
cause Burton A. Dole, Jr. and Thomas A. McDonnell to be appointed to the Nellcor
Board, effective as  of the Effective  Time, for  a term expiring  at the  first
annual meeting of Nellcor's stockholders after the Merger. Mr. Dole is currently
Chairman,  President and  Chief Executive  Officer of  P-B and  Mr. McDonnell is
currently a  director of  P-B. In  addition, Nellcor  has agreed  in the  Merger
Agreement  to nominate Mr.  Dole and Mr.  McDonnell for reelection  at the first
annual meeting of Nellcor's stockholders  following the Merger, and to  nominate
for election as an additional director of Nellcor at such first annual meeting a
person  selected by Nellcor who is not  a current or former officer, director or
employee of P-B and  who is mutually  agreeable to Mr.  Dole and Mr.  McDonnell.
Following  such actions, the Nellcor Board will  consist of nine persons, six of
whom were directors of Nellcor as of the date of the Merger Agreement.

    Set forth below is certain information about each person who is expected  to
be  a member of the Board of Directors of Nellcor as of the Effective Time, with
the information expected to be true at the Effective Time.

    C. RAYMOND LARKIN, JR., Director, President and Chief Executive Officer, age
47. Mr.  Larkin has  been an  officer of  Nellcor since  1983, serving  as  Vice
President,  Sales and Vice President, Sales  and Marketing until his election as
President and Chief Operating  Officer in February 1989  and as Chief  Executive
Officer in November 1989. Mr. Larkin is a director of Heart Technology, Inc. and
Ventritex, Inc.

    BURTON  A. DOLE, JR., Director and Chairman,  age 57. Mr. Dole has served as
President, Chief Executive Officer and Chairman  of the Board of P-B since  1986
and was President and Chief Executive Officer of P-B from 1980 to 1986. Mr. Dole
will  cease serving in such  capacities as of the Effective  Time. Mr. Dole is a
director of the New  England Company, the  Anesthesia Patient Safety  Foundation
and  the Health Industries Manufacturers Association. In December 1994, Mr. Dole
completed a three-year term as Chairman of the Board of the Federal Reserve Bank
of Kansas City.

    ROBERT J. GLASER,  M.D., Director, age  76. Dr. Glaser  is the Director  for
Medical  Science and a Trustee of the  Lucille P. Markey Charitable Trust, which
provides major grants in support of basic biomedical research, positions he  has
held  since 1984 and  1989, respectively. He  is also a  Consulting Professor of
Medicine at Stanford University, where  he served as the  Dean of the School  of
Medicine from 1965 to 1970. Dr. Glaser was a founding member of the Institute of
Medicine  of the National Academy of Sciences.  Dr. Glaser is a director of Alza
Corporation and Hanger Orthopedics, Inc.

    FREDERICK M.  GRAFTON,  Director,  age  69.  Mr.  Grafton  is  a  management
consultant  to several technology companies. He  retired as President of Raychem
Ventures, Inc.,  a subsidiary  of Raychem  Corporation (a  materials  technology
driven   product  company),  in  February   1990.  Mr.  Grafton  joined  Raychem
Corporation in  1962 and  served  as Division  General  Manager and  Group  Vice
President  of Raychem Corporation until 1988 when he became President of Raychem
Ventures, which manages a venture portfolio of Raychem Corporation.

    DONALD L. HAMMOND, Director, age 67.  Mr. Hammond is a technical  consultant
to  several technology companies. Previously, he was Director of Hewlett-Packard
Laboratories of the Hewlett-Packard Company, a manufacturer of computer  systems
and  electronic products. Mr. Hammond joined  Hewlett-Packard in 1959 and served
as a  Founding Director  of  Hewlett-Packard Laboratories  from 1966  until  his
retirement in 1988. He is a director of Mid-Peninsula Bank.

    THOMAS  A.  MCDONNELL,  Director, age  49.  Mr.  McDonnell has  served  as a
director of P-B since April  1994. He has served as  Vice Chairman of the  Board
and  Chief Executive Officer  of DST Systems,  Inc. ("DST"), a  provider of data
processing based services  to the  financial industry, since  October 1984.  Mr.
McDonnell  has served as President of DST  from 1973 until October 1984 and from
March 1987 to the present, and has been its Treasurer since 1973. Mr.  McDonnell
has  been  Executive Vice  President of  Kansas  City Southern  Industries, Inc.
("KCSI"), a holding company and parent of DST,

                                       59
<PAGE>
since February 1987, and a member of  the Office of the Chief Executive of  KCSI
since  1989. He is  a director of  KCSI, Informix Software,  Inc., The Continuum
Corporation, BHA Group, Inc. and First of Michigan Capital Corp.

    WALTER J. MCNERNEY, Director, age 70. Mr. McNerney is a Professor of  Health
Policy  at the Kellogg Graduate School of Management at Northwestern University,
a post he has held since 1982, and has served as Chairman of Walter J.  McNerney
Associates,  a health care  management consulting firm,  since 1983. Previously,
Mr. McNerney was President of the Blue Cross/Blue Shield Associations from  1978
to  1981, and President of the Blue Cross Association from 1961 to 1978. He is a
director of American Health Properties, Hanger Orthopedics, Inc., Medicus, Osteo
Tech, Stanley Works, Value Health, Inc. and Ventritex, Inc.

    EDWIN E. VAN  BRONKHORST, Director, age  71. Mr. van  Bronkhorst has been  a
consultant to various technology companies since 1984 and is currently Treasurer
and Trustee of the David and Lucile Packard Foundation. Previously, he served as
Senior   Vice  President,   Chief  Financial   Officer  and   Treasurer  of  the
Hewlett-Packard Company,  a  manufacturer  of computer  systems  and  electronic
products,  from 1962  until his  retirement in  1984. Mr.  van Bronkhorst joined
Hewlett-Packard in 1953 and served on its Board of Directors from 1962 to  1984.
He is a director of California Water Service Company and Mid-Peninsula Bank.

    Set  forth below is certain information about  each person in addition to C.
Raymond Larkin, Jr. who is expected to be a senior executive officer of  Nellcor
as  of  the Effective  Time, with  the information  expected to  be true  at the
Effective Time.

    LAUREEN DEBUONO, Executive Vice President, Human Resources, General  Counsel
and  Secretary, age  37. Ms.  DeBuono joined  Nellcor in  April 1992  as General
Counsel and Secretary and  currently serves as  Executive Vice President,  Human
Resources,  General Counsel and Secretary. Prior to joining Nellcor, Ms. DeBuono
was Division  and  Corporate Counsel  with  The Clorox  Company,  a  diversified
consumer  products company, from 1987 to 1992, and Corporate Counsel with Varian
Associates, Inc., an electronics device company, from 1984 to 1987.

    MICHAEL P. DOWNEY,  Executive Vice President,  Chief Financial Officer,  age
47.  Mr. Downey joined Nellcor  in 1986 as Corporate  Controller and became Vice
President, Finance in April 1987 and Vice President, Chief Financial Officer  in
July  1989. Mr.  Downey currently serves  as Executive Vice  President and Chief
Financial Officer.  Prior to  joining Nellcor,  Mr. Downey  was Vice  President,
Finance  with Shugart Corporation,  a manufacturer of disk  drives, from 1984 to
1986. Mr. Downey also is a director of Emulex Corporation.

    ROBERT L. DOYLE, Executive Vice President, Worldwide Sales and Distribution,
age 52. Mr. Doyle was  elected Senior Vice President of  P-B in 1988 and  became
Senior  Vice President, Marketing in 1991. Mr.  Doyle will cease serving in such
capacity as of the Effective Date.

    RUSSELL B. HAYS, Executive Vice  President, Nellcor Operations, age 50.  Mr.
Hays  joined Nellcor as its Executive Vice President, Nellcor Operations in June
1995. Following consummation of  the Merger, Mr. Hays'  title will be  Executive
Vice President, President, Hospital Business. Prior to joining Nellcor, Mr. Hays
served  as the President  and Chief Executive  Officer of Sequenom  from 1993 to
1995. Previously, Mr. Hays  served as President and  Chief Executive Officer  of
Enzytech, Inc. from 1992 to 1993, and in various capacities at Baxter Healthcare
Corporation  from 1985 to 1992.  He also served as  a General Manager at Stryker
Corporation from  1981 to  1985 and  in various  capacities at  Baxter  Travenol
Laboratories,  Inc.  from 1976  to 1981.  Mr.  Hays also  serves as  director of
Activated Cell Therapy, Inc.

    JOHN H.  MORROW,  Executive  Vice President,  President,  Home  Health  Care
Business,  age 50. Mr. Morrow was elected Vice  President of P-B in 1979 and has
served as its Executive Vice President  and Chief Operating Officer since  1989.
Mr. Morrow will cease serving in such capacities as of the Effective Time. Prior
to  joining P-B, Mr. Morrow was a management consultant with McKinsey & Company,
Inc. from 1970 to 1979.

                                       60
<PAGE>
    It is contemplated that Messrs. Dole  and Morrow will enter into  employment
agreements  with Nellcor that  will become effective at  the Effective Time. See
"The Merger -- Interests of Certain Persons in the Merger."

SECURITY OWNERSHIP OF MANAGEMENT

    As of the  June 30, 1995,  directors and executive  officers of Nellcor  and
their   affiliates  were  beneficial  owners   of  approximately  1.15%  of  the
outstanding shares of  Nellcor Common  Stock (exclusive of  any shares  issuable
upon  the exercise of stock options remaining unexercised as of such date. As of
June 30, 1995, directors and executive officers of P-B and their affiliates were
beneficial owners of approximately 1.39% of the outstanding shares of P-B Common
Stock (exclusive of any shares issuable  upon the exercise of any stock  options
remaining unexercised as of such date.

    Additional  information concerning voting securities  of Nellcor and P-B and
the principal holders thereof is included in the documents filed by Nellcor  and
P-B  with the Commission under the Exchange Act. See "Available Information" and
"Incorporation of Documents by Reference."

POST-MERGER DIVIDEND POLICY

    Nellcor has never declared  any cash dividends on  the Nellcor Common  Stock
and  does not  anticipate paying such  dividends in the  foreseeable future. Any
future determination to pay dividends will be at the discretion of the Board  of
Directors of the combined companies.

               COMPARATIVE PER SHARE PRICES AND DIVIDEND POLICIES

    Both the Nellcor Common Stock and the P-B Common Stock are listed and traded
on Nasdaq. The following table sets forth the high and low sale prices per share
of  Nellcor  Common  Stock  and  P-B  Common  Stock  for  the  calendar quarters
indicated, as reported by Nasdaq.

   
<TABLE>
<CAPTION>
                                                                 NELLCOR                 P-B
                                                               COMMON STOCK          COMMON STOCK
                                                           --------------------  --------------------
                                                             HIGH        LOW       HIGH        LOW
                                                           ---------  ---------  ---------  ---------
<S>                                                        <C>        <C>        <C>        <C>
Calendar 1993:
  First Quarter..........................................  $  34.25   $  20.00   $  34.00   $  20.75
  Second Quarter.........................................     25.25      17.50      23.00      13.25
  Third Quarter..........................................     23.50      19.00      22.75      16.25
  Fourth Quarter.........................................     26.50      19.75      17.50      14.50
Calendar 1994:
  First Quarter..........................................     29.50      24.25      21.75      15.00
  Second Quarter.........................................     28.75      24.375     22.75      16.75
  Third Quarter..........................................     31.50      26.00      20.00      15.25
  Fourth Quarter.........................................     34.00      28.25      26.25      15.75
Calendar 1995:
  First Quarter..........................................     38.25      31.50      24.50      20.25
  Second Quarter.........................................     47.75      36.00      40.50      21.75
  Third Quarter (through July 20)........................     50.75      44.00      43.625     38.375
</TABLE>
    

   
    On May 19, 1995, the  last trading day prior  to announcement of the  Merger
Agreement, the closing sales prices of Nellcor Common Stock and P-B Common Stock
as reported by Nasdaq were $41.25 per share and $26.125 per share, respectively.
Based  on the  Exchange Ratio  of 0.88,  the equivalent  per share  value of P-B
Common Stock as of  such date was  $36.30. On July 20,  1995, the closing  sales
prices  of Nellcor Common Stock and P-B  Common Stock as reported by Nasdaq were
$47.625 per share  and $41.125 per  share, respectively. Based  on the  Exchange
Ratio  of 0.88, the  equivalent per share value  of P-B Common  Stock as of such
date was $41.91.
    

    Because the Exchange Ratio is fixed at 0.88 and because the market price  of
Nellcor  Common Stock is subject to fluctuation,  the market value of the shares
of Nellcor Common Stock  that holders of  P-B Common Stock  will receive in  the
Merger    may   increase    or   decrease    prior   to    and   following   the

                                       61
<PAGE>
Merger. STOCKHOLDERS ARE URGED TO  OBTAIN CURRENT MARKET QUOTATIONS FOR  NELLCOR
COMMON  STOCK AND P-B COMMON  STOCK. NO ASSURANCE CAN BE  GIVEN AS TO THE FUTURE
PRICES OR MARKETS FOR NELLCOR COMMON STOCK OR P-B COMMON STOCK.

    In August 1976, P-B initiated payment  of a regular quarterly dividend.  The
current  dividend  of $0.03  per share  was established  in March  1990. Pending
consummation of the Merger, P-B has  agreed to cease paying dividends after  its
May 1995 regular cash dividend. See "The Merger Agreement -- Certain Covenants."
No  dividends have been declared or paid on Nellcor Common Stock since Nellcor's
incorporation, nor  are  any  such  dividends  expected  to  be  paid  following
consummation of the Merger.

                                       62
<PAGE>
          UNAUDITED PRO FORMA COMBINED CONDENSED FINANCIAL STATEMENTS

    The  following unaudited  pro forma combined  condensed financial statements
assume a business combination  between Nellcor and P-B  accounted for using  the
pooling  of interests  method of  accounting and  are based  upon the respective
historical financial statements and notes thereto of Nellcor and P-B, which  are
incorporated  by reference in this Proxy Statement/Prospectus. The unaudited pro
forma  combined  condensed  balance  sheet  combines  Nellcor's  April  2,  1995
unaudited  consolidated  balance  sheet  with  P-B's  April  30,  1995 unaudited
consolidated  balance  sheet.  The   unaudited  pro  forma  combined   condensed
statements  of operations combine  Nellcor's historical results  for each of the
three fiscal years  in the  period ended  July 3,  1994 and  the unaudited  nine
months  ended April 2, 1995 and April  3, 1994 with P-B's historical results for
each of the  two fiscal years  in the period  ended January 31,  1994, the  year
ended  December 31, 1991 and the unaudited  nine months ended April 30, 1995 and
1994, respectively.

    The unaudited balance sheet of Nellcor at April 2, 1995 and P-B at April 30,
1995 and the unaudited statement of  operations for the nine months ended  April
2,  1995 and April 3, 1994  of Nellcor and ended April  30, 1995 and 1994 of P-B
have been prepared on the same basis as the historical information derived  from
audited  financial statements. In the opinion  of the managements of Nellcor and
P-B, respectively,  the  unaudited  financial  statements  of  Nellcor  and  P-B
referred  to above, as the  case may be, from which  such data have been derived
contain all adjustments, consisting of normal recurring accruals, necessary  for
the fair presentation of the results for such periods.

    The   unaudited  pro  forma  combined  condensed  financial  statements  are
presented for illustrative purposes only  and are not necessarily indicative  of
the  operating results  or financial  position that  would have  occurred if the
Merger had been consummated at the  beginning of the earliest period  presented,
nor are they necessarily indicative of the future operating results or financial
position.

    These  unaudited pro forma combined condensed financial statements are based
on, and  should  be  read  in  conjunction  with,  the  historical  consolidated
financial   statements  and  the  related  notes  thereto  of  Nellcor  and  P-B
incorporated by reference in this Proxy Statement/Prospectus.

                                       63
<PAGE>
              UNAUDITED PRO FORMA COMBINED CONDENSED BALANCE SHEET
                                 (IN THOUSANDS)
                                     ASSETS

<TABLE>
<CAPTION>
                                                     NELLCOR APRIL         P-B          PRO FORMA    COMBINED PRO
                                                        2, 1995      APRIL 30, 1995    ADJUSTMENTS      FORMA
                                                     --------------  ---------------  -------------  ------------
<S>                                                  <C>             <C>              <C>            <C>
Current assets:
  Cash & cash equivalents..........................   $    100,885     $     1,162     $   --         $  102,047
  Marketable securities............................         42,395         --              --             42,395
  Trade notes and accounts receivable, net.........         38,634          75,907         --            114,541
  Inventories......................................         25,614          62,114         --             87,728
  Deferred income taxes and other current assets...          6,638          10,751         9,700(a)       27,089
                                                     --------------  ---------------  -------------  ------------
Total current assets...............................        214,166         149,934         9,700         373,800
                                                     --------------  ---------------  -------------  ------------
Net property and equipment.........................         33,977          91,303         --            125,280
Other assets and goodwill, net.....................         15,415          36,415         --             51,830
                                                     --------------  ---------------  -------------  ------------
                                                      $    263,558     $   277,652     $   9,700      $  550,910
                                                     --------------  ---------------  -------------  ------------
                                                     --------------  ---------------  -------------  ------------

                                       LIABILITIES & STOCKHOLDERS' EQUITY

Current liabilities:
  Notes payable....................................   $    --          $    18,700     $   --         $   18,700
  Accounts payable.................................         10,799          13,198         --             23,997
  Accrued liabilities..............................         17,611           7,831        15,500(b)       40,942
  Current maturities of long-term debt.............        --                9,533         --              9,533
  Income taxes payable.............................          3,660           3,654         --              7,314
  Other............................................          6,648          14,864         --             21,512
                                                     --------------  ---------------  -------------  ------------
Total current liabilities..........................         38,718          67,780        15,500         121,998
                                                     --------------  ---------------  -------------  ------------
Long-term debt, less current maturities............        --               54,573         --             54,573
Deferred compensation and pensions.................        --               20,352         --             20,352
Deferred revenue...................................        --               10,775         --             10,775
                                                                     ---------------  -------------  ------------
                                                                            85,700         --             85,700
                                                                     ---------------  -------------  ------------
                                                                                           9,700(a)
Total stockholders' equity.........................        224,840         124,172       (15,500)(b)     343,212
                                                     --------------  ---------------  -------------  ------------
                                                      $    263,558     $   277,652     $   9,700      $  550,910
                                                     --------------  ---------------  -------------  ------------
                                                     --------------  ---------------  -------------  ------------
<FN>
- ------------------------
(a)  Pro forma adjustments as described in Note 3.

(b)  Pro forma adjustments as described in Note 4.
</TABLE>

 See notes to the unaudited pro forma combined condensed financial statements.

                                       64
<PAGE>
         UNAUDITED PRO FORMA COMBINED CONDENSED STATEMENT OF OPERATIONS
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)

<TABLE>
<CAPTION>
                                            FISCAL YEAR ENDED                      NINE MONTHS ENDED
                                ------------------------------------------   -----------------------------
                                JULY 3, 1994   JULY 4, 1993   JULY 5, 1992   APRIL 2, 1995   APRIL 3, 1994
                                ------------   ------------   ------------   -------------   -------------
<S>                             <C>            <C>            <C>            <C>             <C>
Net revenue...................    $544,227       $518,246       $452,286       $446,884        $406,265
Cost of goods sold............     274,290        258,670        234,879        225,927         208,851
                                ------------   ------------   ------------   -------------   -------------
Gross profit..................     269,937        259,576        217,407        220,957         197,414
                                ------------   ------------   ------------   -------------   -------------
Operating Expenses:
Research and development......      48,867         48,545         46,256         34,800          33,765
Selling, general and
 administrative...............     169,691        152,069        139,723        128,356         126,116
Restructuring charges.........      43,669         --             --              2,654          34,655
                                ------------   ------------   ------------   -------------   -------------
                                   262,227        200,614        185,979        165,810         194,536
                                ------------   ------------   ------------   -------------   -------------
Income from operations........       7,710         58,962         31,428         55,147           2,878
Litigation settlements, net...     (13,000)                                                       2,000
Interest expense..............      (4,565)        (3,720)        (2,064)        (4,846)         (3,381)
Interest income and other,
 net..........................       3,695          4,011          2,255          4,834           4,105
Costs associated with
 unsolicited offer............      --             --             --             (5,249)         --
                                ------------   ------------   ------------   -------------   -------------
Income/(loss) before income
 taxes........................      (6,160)        59,253         31,619         49,886           5,602
Provision for income taxes....         262         19,538          9,752         14,779           6,076
                                ------------   ------------   ------------   -------------   -------------
Net income/(loss) from
 operations...................    $ (6,422)      $ 39,715       $ 21,867       $ 35,107        $   (474)
                                ------------   ------------   ------------   -------------   -------------
                                ------------   ------------   ------------   -------------   -------------
Net income/(loss) from
 operations per share.........    $  (0.23)      $   1.46       $   0.83       $   1.26        $  (0.02)
                                ------------   ------------   ------------   -------------   -------------
                                ------------   ------------   ------------   -------------   -------------
Shares used to compute
 income/(loss) from operations
 per share....................      27,364         27,140         26,504         27,961          27,797
                                ------------   ------------   ------------   -------------   -------------
                                ------------   ------------   ------------   -------------   -------------
</TABLE>

 See notes to the unaudited pro forma combined condensed financial statements.

                                       65
<PAGE>
                          NOTES TO UNAUDITED PRO FORMA
                    COMBINED CONDENSED FINANCIAL STATEMENTS

    1.   The unaudited  pro  forma combined  condensed financial  statements  of
Nellcor  and P-B  give retroactive  effect to  the Merger  using the  pooling of
interests method  of  accounting and,  as  a  result, the  unaudited  pro  forma
combined  condensed balance sheet and statements  of operations are presented as
if the combining  companies had  been combined  for all  periods presented.  The
unaudited  pro  forma combined  condensed financial  statements will  become the
historical financial statements of Nellcor upon issuance of financial statements
for a period that includes the date of the acquisition. The unaudited pro  forma
combined  condensed financial statements reflect the issuance of 0.88 of a fully
paid and  nonassessable share  of Nellcor  Common Stock  for each  share of  P-B
Common  Stock (other  than shares  of P-B Common  Stock held  in P-B's treasury,
which will be canceled)  to effect the  Merger. The actual  number of shares  of
Nellcor  Common Stock to be  issued will be determined  at the effective time of
the Merger based on the  Exchange Ratio and the number  of shares of P-B  Common
Stock  then outstanding.  The unaudited  pro forma  combined condensed financial
statements, including the notes thereto, should be read in conjunction with  the
historical  consolidated financial statements of Nellcor and P-B incorporated by
reference in this Proxy Statement/Prospectus.

    2.   The  unaudited pro  forma  combined condensed  balance  sheet  combines
Nellcor's  April 2, 1995  unaudited consolidated balance  sheet with P-B's April
30,  1995  unaudited  consolidated  balance  sheet.  The  unaudited  pro   forma
statements  of operations combine  Nellcor's historical results  for each of the
three fiscal years  in the  period ended  July 3,  1994 and  the unaudited  nine
months  ended April 2, 1995 and  April 3, 1994 with the  P-B results for each of
the two  fiscal years  in the  period ended  January 31,  1994, the  year  ended
December  31, 1991 and the unaudited nine  months ended April 30, 1995 and 1994,
respectively.

    3.  The unaudited pro forma combined condensed statements of operations  for
the  period ended July 3, 1994 and the nine months ended April 2, 1995 and April
3, 1994 reflect an adjustment to  reduce P-B's valuation allowance provided  for
its  deferred tax assets based on the combined income from operations before tax
of Nellcor and P-B as required by Statement of Financial Accounting Standard No.
109. These adjustments  have the effect  of decreasing unaudited  net loss  from
operations  by approximately  $4.8 million and  $3.4 million for  the year ended
July 3,  1994  and  the nine  months  ended  April 3,  1994,  respectively,  and
increasing  unaudited  net income  by approximately  $2.9  million for  the nine
months ended April 2,  1995. The cumulative effect  of reducing P-B's  valuation
allowance   provided  for  its  deferred  tax   assets  at  April  30,  1995  is
approximately $9.7 million.

    4.  The unaudited  pro forma data are  presented for informational  purposes
only and do not give effect to any synergies that may occur due to the combining
of  Nellcor's and P-B's existing operations. Nellcor expects to incur charges to
operations currently estimated to be between $20 million and $30 million in  the
quarter ended October 1, 1995, the quarter in which the Merger is expected to be
consummated,  to reflect costs  associated with combining  the operations of the
two companies, primarily  the closing  of duplicate  facilities and  transaction
fees  and costs incident to the Merger.  An estimated charge, at the midpoint of
the above range, after effecting for estimated tax benefits, of $15.5 million is
reflected in the unaudited pro forma combined condensed balance sheet and is not
included in the unaudited pro forma combined condensed statement of  operations.
This range is a preliminary estimate only and therefore is subject to change.

    5.   There were  no material differences between  the accounting policies of
Nellcor and P-B during the periods presented.

    6.   As  a  result of  the  convention  selected to  combine  the  financial
information  of Nellcor and  P-B, the results  of operations of  P-B for the one
month period ended January 31,  1992 and the three  month period ended July  31,
1994,  do not appear in  any of the periods  presented under Unaudited Pro Forma
Combined Condensed Statement  of Operations.  P-B changed  its year  end from  a
calendar year end to a fiscal year ended January 31, effective February 1, 1992.
The one month period ended

                                       66
<PAGE>
January  31, 1992 (transition period) was audited. Selected historical financial
data for P-B for the one month period are as follows: net revenue $19.7 million,
loss from operations $1.5  million, net loss from  operations $2.2 million,  net
loss  from operations per share of $0.20 and 11.6 million shares used to compute
net loss from operations per share. No cash dividends were declared or paid with
respect to the transition period. Selected historical financial data for P-B for
the unaudited three month period ended July 31, 1994 are as follows: net revenue
$84.0 million, income from operations  $5.3 million, net income from  operations
$4.2  million, net income  from operations per  share of $0.34  and 12.5 million
shares used to compute net income from operations per share. A cash dividend  of
$0.03 per share was declared by P-B with respect to the three month period ended
July 31, 1994.

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                  THE NELLCOR 1995 MERGER STOCK INCENTIVE PLAN

    At  the Nellcor Special Meeting, Nellcor  stockholders will be asked to vote
on a proposal to adopt the 1995  Merger Stock Incentive Plan (the "1995  Plan").
The  purpose of  the 1995 Plan  is to  comply with Nellcor's  obligations in the
Merger Agreement to issue Replacement Options (as defined below) in exchange for
certain outstanding  options  to purchase  P-B  Common Stock.  Such  Replacement
Options  will be  issued at  the Effective Time,  subject to  the conditions set
forth below under "-- 1995 Plan --  Types of Awards," and no additional  options
will  be issued thereafter under the 1995 Plan. If the Nellcor Share Proposal is
not approved  or the  Merger  is otherwise  not  consummated, Nellcor  will  not
implement  the 1995 Plan Proposal.  Approval of the 1995  Plan Proposal is not a
condition to consummation of the Merger.

    Pursuant to the  Merger Agreement,  Nellcor has  agreed to  provide for  the
issuance of options to purchase Nellcor Common Stock (the "Replacement Options")
(a)  which  evidence  converted  options  previously  granted  under  P-B's 1979
Employee Stock Benefit Plan  (the "1979 P-B Plan")  that remain outstanding  and
unexercised as of the Effective Time, and (b) which evidence substituted options
in  replacement of  options previously granted  under P-B's  1988 Employee Stock
Benefit Plan (the  "1988 P-B Plan")  that had their  vesting and  exercisability
accelerated  as  a  result of  the  Merger  and expired  unexercised  as  of the
Effective Time (collectively, the options referred  to in (a) and (b), the  "P-B
Options").  The  number  of  shares  of Nellcor  Common  Stock  covered  by each
Replacement Option  will  equal  the  number  of  shares  of  P-B  Common  Stock
underlying  the corresponding P-B  Option multiplied by 0.88  (rounded up to the
nearest whole share). The exercise price  of each Replacement Option will  equal
the exercise price of the corresponding P-B Option divided by 0.88 (rounded down
to  the nearest penny). Nellcor has also agreed in the Merger Agreement that the
terms of the Replacement Options  shall be the same  as those of the  underlying
P-B  Options,  except for  the aforementioned  changes  and that  any provisions
pertaining to acceleration  of vesting  and exercisability  as a  result of  the
Merger shall not apply.

    As  of July 19, 1995, P-B Options to purchase an aggregate of 883,583 shares
of P-B Common Stock at a weighted average exercise price of $22.13 per share (at
exercise prices ranging from $9.88 to  $29.75 per share) were outstanding.  Such
P-B  Options were held by approximately 200  persons. Assuming that none of such
options are exercised prior  to the Effective Time,  a maximum of  approximately
779,000  shares  of Nellcor  Common Stock  would  be required  for the  grant of
Replacement Options under the 1995 Plan. However, fewer shares of Nellcor Common
Stock will be required,  and may be  granted to fewer  persons than the  current
number  of holders of P-B Options, to  the extent that P-B Options are exercised
prior to the Effective Time.  The number of any such  P-B Options, if any,  that
may be exercised prior to the Effective Time cannot presently be determined.

    Nellcor  is  seeking stockholder  approval for  the  authorization of  up to
779,000 shares of  Nellcor Common Stock  under the 1995  Plan. However,  Nellcor
intends  to implement the 1995  Plan only to the extent  of the actual number of
shares of Nellcor Common  Stock required to cover  the Replacement Options  that
are  required  to be  issued. Such  number  will not  be determinable  until the
Effective Time. Following the issuance of the Replacement Options, no additional
awards will be available under the 1995 Plan.

    THE NELLCOR  BOARD  HAS UNANIMOUSLY  APPROVED  THE 1995  PLAN  PROPOSAL  AND
UNANIMOUSLY RECOMMENDS THAT HOLDERS OF SHARES OF NELLCOR COMMON STOCK VOTE "FOR"
APPROVAL OF SUCH PROPOSAL.

    The essential features of the 1995 Plan are summarized below.

THE 1995 PLAN

    PURPOSE.   The purpose of  the 1995 Plan is to  allow Nellcor to comply with
its obligations under the Merger Agreement to issue the Replacement Options. The
intent and effect of the 1995 Plan is to

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<PAGE>
reflect the right of holders of P-B Options to acquire shares of Nellcor  Common
Stock  in  lieu of,  but not  in addition  to,  the shares  of P-B  Common Stock
underlying unexercised  P-B  Options  held  by them  immediately  prior  to  the
Effective Time.

    ADMINISTRATION.    The  1995  Plan  will  be  administered  by  a  committee
designated by the Nellcor Board (the "Committee"). Subject to the provisions  of
the  1995 Plan,  the Committee  shall have the  authority to  interpret the 1995
Plan, to prescribe, amend and rescind rules and regulations relating to the 1995
Plan and  to make  all other  determinations deemed  necessary or  advisable  in
administering  the 1995 Plan. All  decisions, determinations and interpretations
of the Committee shall be conclusive and binding on all participants.

    TYPES OF AWARDS.   Awards under  the 1995  Plan will consist  solely of  the
issuance  of Replacement Options to each holder  of P-B Options. With respect to
all P-B  Options  that  are  designed to  qualify  as  incentive  stock  options
("Incentive  Stock Options")  under Section 422  of the  Code, the corresponding
Replacement Options  shall  also  be  designed to  qualify  as  Incentive  Stock
Options.  With respect to all P-B Options that are not described in Sections 422
or  423  of  the  Code   ("Non-Qualified  Stock  Options"),  the   corresponding
Replacement  Options shall also  be Non-Qualified Stock  Options. No Replacement
Options will be issued under the Plan to  any holder of a P-B Option unless  and
until  such holder  has either  (i) returned  the agreement  evidencing such P-B
Option to Nellcor for  cancellation, or (ii) delivered  to Nellcor (a)  evidence
reasonably  satisfactory to  Nellcor of the  loss, theft or  destruction of such
option agreement  and  (b)  indemnity or  security  reasonably  satisfactory  to
Nellcor.

    AVAILABLE  SHARES.  A total  of 779,000 shares of  Nellcor Common Stock have
been reserved for  issuance under the  1995 Plan. However,  as noted above,  the
number  of shares actually covered by Replacement Options will be less than that
number to the extent that P-B Options are exercised prior to the Effective Time.

    ELIGIBLE INDIVIDUALS.  Only holders of  P-B Options are eligible to  receive
Replacement  Options under  the 1995  Plan. All such  persons were,  at the time
their P-B Options were awarded,  employees of P-B with managerial,  supervisory,
professional,   scientific,   engineering   or   similar   responsibilities.  No
Replacement Option is transferable by the optionee during his lifetime.

TERMS OF REPLACEMENT OPTIONS

    The terms of the Replacement Options granted under the 1995 Plan will be  as
set forth below:

        (a)   NUMBER OF  SHARES COVERED.   Each Replacement Option  will cover a
    number of shares of  Nellcor Common Stock (rounded  up to the nearest  whole
    share)  equal to  the number of  shares of  P-B Common Stock  covered by the
    corresponding P-B Option multiplied by 0.88, the Exchange Ratio.

        (b)  EXERCISE  PRICE.  The  exercise price per  share of Nellcor  Common
    Stock (rounded down to the nearest penny) covered by each Replacement Option
    will  equal the  per share  exercise price  of the  corresponding P-B Option
    divided by 0.88, the Exchange Ratio.

        (c)  OPTION TERM.  The term of each Replacement Option will be the  same
    as  the term of the corresponding P-B Option, except that the termination of
    the 1988 P-B  Options as a  result of  the Merger will  be disregarded.  The
    maximum  term of the P-B Options is ten years from the date of initial grant
    of such P-B Options.

        (d)   VESTING.   The vesting  restrictions, if  any, contained  in  each
    Replacement  Option will  be the same  as the vesting  restrictions, if any,
    contained in the corresponding P-B  Option, except that any acceleration  of
    the 1988 P-B Options as a result of the Merger will be disregarded.

        (e)   CERTAIN  ADJUSTMENTS.   The number of  shares covered  by, and the
    exercise  price  of,  each  Replacement  Option  may,  in  the   Committee's
    discretion,   be  adjusted  appropriately  to  reflect  any  change  in  the
    capitalization   of    Nellcor    resulting   from    any    reorganization,
    recapitalization, stock split-up or combination of shares, or the payment of
    a  stock dividend or other increase or  decrease in the Nellcor Common Stock
    effected without receipt of consideration by Nellcor.

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<PAGE>
    EXERCISE OF OPTIONS.  The exercise price for all Replacement Options must be
paid to Nellcor at  the time of  exercise in cash,  provided that the  Committee
may,  in its  discretion, permit the  exercise price  to be paid  by transfer to
Nellcor of shares of Nellcor Common Stock owned by the optionee, valued at  fair
market value as of the exercise date. With respect to Replacement Options issued
in substitution of P-B Options issued under the 1988 P-B Plan ("1988 Replacement
Options"),  the Committee also may, in its discretion, permit the exercise price
to be paid by  delivery of an  irrevocable direction to  a securities broker  to
sell shares of Nellcor Common Stock and deliver the sale proceeds to Nellcor, or
to  arrange for  the delivery to  Nellcor of cash  in any other  manner that the
Committee shall  permit; provided  that  the payment  method described  in  this
sentence  is not available to an optionee who is subject to Section 16(b) of the
Exchange Act. The Committee also may, in its discretion, permit the holder of  a
Replacement  Option to surrender  all or part  of such option  in exchange for a
payment (in cash, shares of Nellcor Common Stock valued at fair market value  on
the  date of surrender,  or any combination  thereof) in an  amount equal to the
difference between the aggregate  fair market value (as  of the surrender  date)
and  the  aggregate exercise  price of  the shares  as to  which such  option is
surrendered. An option may be exercised  only while the optionee is an  employee
of  Nellcor or its  subsidiaries or, in  the event of  termination of employment
otherwise than by reason of death or total disability, within three months after
termination of employment  (but not  later than the  expiration of  term of  the
option).

    WITHHOLDING  TAXES.  No shares  of Nellcor Common Stock  may be issued under
the 1995  Plan until  the optionee  has made  arrangements satisfactory  to  the
Committee for the satisfaction of federal, state and local income and employment
tax  withholding obligations.  The optionee may  elect to  have Nellcor withhold
from the shares otherwise  deliverable upon exercise of  his or her  Replacement
Option  a number of shares having a fair market value sufficient to satisfy such
withholding obligations. Such election will  be subject to certain  restrictions
if made by an optionee who is subject to Section 16(b) of the Exchange Act.

ACCELERATION AND/OR TERMINATION IN CERTAIN CIRCUMSTANCES

    (A)  1988 REPLACEMENT  OPTIONS.  Each  1988 Replacement  Option shall become
exercisable for 100% of the shares covered  thereby (a) for a period of 30  days
preceding  any  of the  events  described in  (x)  below, and  shall,  except as
provided in the next  sentence, terminate upon the  occurrence of such event  if
not  previously exercised,  and (b)  upon the  occurrence of  any of  the events
described in (y)  or (z)  below: (x) a  merger of,  or consolidation  involving,
Nellcor  in which Nellcor  Common Stock is converted  into securities of another
corporation or into cash; a plan of complete liquidation of Nellcor (whether  or
not  in connection with a sale of  all or substantially all of Nellcor's assets)
shall be adopted; or any other transaction  as a result of which Nellcor  Common
Stock  shall no longer be publicly traded,  in each case excluding a transaction
solely for the purpose of reincorporating Nellcor in a different jurisdiction or
recapitalizing the Nellcor Common Stock; (y) 40 percent or more of the  combined
voting  power of the then outstanding  voting securities of Nellcor shall become
beneficially owned,  directly  or indirectly,  by  one or  more  persons  acting
together,  other  than  Nellcor;  or  (z)  unless  otherwise  determined  by the
Committee in its sole discretion, any purchase of Nellcor Common Stock shall  be
publicly  disclosed pursuant to a  tender offer or exchange  offer to acquire 20
percent or more of the outstanding Nellcor  Common Stock by one or more  persons
acting together, other than Nellcor; or a sale, exchange or other disposition of
all  or substantially all  of the assets  of Nellcor. At  its discretion, and on
such terms and conditions  as it deems appropriate,  the Committee may  provide,
that  upon consummation of any of the events described in clause (x), (y) or (z)
of the preceding sentence, any 1988 Replacement Options that remain  unexercised
shall  be  assumed  by the  successor  corporation,  or a  parent  or subsidiary
thereof, or shall be substituted for by a similar option, covering the stock  of
the  successor corporation, or a parent  or subsidiary thereof, with appropriate
adjustments as to  the number and  kind of  shares and exercise  prices. In  the
event  that  the  Committee  provides for  such  assumption  or  substitution of
options, the assumed  or substituted  options shall  continue to  be subject  to
their  original vesting schedules notwithstanding the provision for acceleration
of vesting set forth above.

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<PAGE>
    (B) 1979  REPLACEMENT  OPTIONS.   Subject  to  any required  action  by  the
stockholders,  if  Nellcor  is  the  surviving  corporation  in  any  merger  or
consolidation, any  Replacement Option  issued in  substitution of  P-B  Options
issued  under the 1979 P-B Plan ("1979 Replacement Options") will pertain to and
apply to the securities  to which a  holder of the number  of shares of  Nellcor
Common  Stock subject to such 1979  Replacement Option would have been entitled.
Upon a dissolution of Nellcor, or a merger or consolidation in which Nellcor  is
not  the surviving  corporation, every  1979 Replacement  Option will terminate;
PROVIDED,  HOWEVER,  that   in  the   case  of  such   dissolution,  merger   or
consolidation, then during the period thirty days prior to the effective date of
such  event,  each holder  of a  1979 Replacement  Option will  have a  right to
exercise such 1979 Replacement Option, in whole or in part.

    ACCELERATION UPON TERMINATION  OF EMPLOYMENT.   If an optionee's  employment
with  Nellcor or P-B is  terminated following the Effective  Time as a result of
death, total disability, retirement  or any reason  unrelated to the  optionee's
employment  performance, then  each Replacement Option  shall become exercisable
for 100% of the  shares covered thereby, in  whole or in part,  at any time  and
from  time to time  within three months  after the date  of such termination (12
months thereafter in the  case of death  or total disability),  but in no  event
after the expiration date of the Replacement Option.

    AMENDMENT.   The Nellcor Board  may amend the 1995 Plan  at any time and for
any reason, subject to certain restrictions  on the ability to adversely  affect
awards  previously granted  thereunder and  to any  legal requirement  to obtain
stockholder approval.

    RULE 16B-3 COMPLIANCE.   Transactions under  the 1995 Plan  are intended  to
comply  with all applicable conditions of Rule 16b-3 or its successors under the
Exchange Act. To the extent any provision of the 1995 Plan, or any action of the
Committee, fails so to comply, such provision or action will be deemed null  and
void  to the extent that  is permitted by applicable  law and that the Committee
deems advisable; PROVIDED,  HOWEVER, that no  such provision or  action will  be
deemed  null and void solely  as a result of the  failure of the stockholders of
Nellcor to approve the Plan.

    SECTION 424(A) COMPLIANCE.  Replacement  Options issued under the 1995  Plan
are  intended to comply with all applicable  conditions of Section 424(a) of the
Code. To  the extent  any provision  of  the 1995  Plan, or  any action  of  the
Committee,  fails to so comply, such provision or action will be deemed null and
void to the extent that is permitted  by applicable law and the Committee  deems
reasonable.

FEDERAL INCOME TAX CONSEQUENCES RELATING TO THE 1995 PLAN

    The following is a brief summary of the current United States federal income
tax rules generally applicable to the awards under the 1995 Plan.

    NON-QUALIFIED  STOCK OPTIONS.  An optionee  is not subject to federal income
tax upon grant of  a Non-Qualified Stock  Option. At the  time of exercise,  the
optionee will realize compensation income (subject to withholding) to the extent
that  the then fair market value of  the Nellcor Common Stock exceeds the option
price. The amount of such income  will constitute an addition to the  optionee's
tax  basis in the optioned stock. Sale of the shares will result in capital gain
or loss (long-term or  short-term depending on  the optionee's holding  period).
Nellcor  is entitled to a business expense deduction at the same time and to the
same extent that the optionee realizes compensation income.

    INCENTIVE STOCK OPTIONS.   Incentive  Stock Options awarded  under the  1995
Plan  are intended to constitute "incentive  stock options" under Section 422 of
the Code. An optionee is not subject to federal income tax upon either the grant
or exercise  of an  Incentive Stock  Option. If  the optionee  holds the  shares
acquired  upon exercise  for at  least one year  after issuance  of the optioned
shares and  until  at least  two  years after  grant  of the  option,  then  the
difference between the amount realized on a subsequent sale or other disposition
of  shares and the option price will  constitute long-term capital gain or loss.
Nellcor will not  be entitled  to any  deduction with  respect to  the grant  or
exercise of the Incentive Stock Option.

    If  the optionee sells  the shares acquired under  an Incentive Stock Option
before the expiration of the requisite holding period, he/she will be deemed  to
have made a "disqualifying disposition" of the

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<PAGE>
shares  and will realize compensation income in the year of disposition equal to
the lesser of  the fair market  value of the  shares at exercise  or the  amount
realized  on their  disposition over  the option price  of the  shares. Any gain
recognized upon a  disqualifying disposition  in excess of  the ordinary  income
portion  will constitute  either short-term  or long-term  capital gain.  In the
event of a  disqualifying disposition, Nellcor  will be entitled  to a  business
expense  deduction  in the  amount of  the compensation  income realized  by the
optionee.

    The option  spread  on the  exercise  of an  Incentive  Stock Option  is  an
adjustment  in computing  alternative minimum  taxable income.  No adjustment is
required, however,  if the  optionee  made a  disqualifying disposition  of  the
shares in the same year as he is taxed on the exercise.

NEW PLAN BENEFITS

    No  benefits  will be  received under  the 1995  Plan by  any person  who is
presently a director, officer or employee of Nellcor.

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<PAGE>
                           THE AMENDMENT TO NELLCOR'S
                           1994 EQUITY INCENTIVE PLAN

    At  the Nellcor Special Meeting, Nellcor  stockholders will be asked to vote
on a  proposed amendment  to Nellcor's  1994 Equity  Incentive Plan  (the  "1994
Plan")  to increase the number of shares authorized for issuance thereunder from
1,500,000 to 2,500,000.  If the Nellcor  Share Proposal is  not approved or  the
Merger  is otherwise not  consummated, Nellcor will not  implement the 1994 Plan
Amendment Proposal.  Approval of  the  1994 Plan  Amendment  Proposal is  not  a
condition to consummation of the Merger.

    The  1994 Plan,  which was  approved by  Nellcor's stockholders  at the 1994
annual meeting, provides  for the  issuance of  stock options  and stock  awards
covering  up to  1,500,000 shares of  Nellcor Common Stock.  Stock awards issued
under the  1994  Plan may  be  made in  the  form of  stock  options  (including
"incentive  stock options" as  provided in Section  422 of the  Code and options
that do not qualify as incentive stock options ("nonqualified stock  options")),
and  stock grants or purchases. The Nellcor  Board has concluded that the number
of shares  authorized under  the 1994  Plan will  not be  sufficient to  achieve
Nellcor's  objectives following the Merger. In particular, immediately following
the Merger Nellcor  will have  outstanding 28,120,080 shares  of Nellcor  Common
Stock  (based upon the capitalization of Nellcor and P-B as of July 19, 1995 and
assuming no exercise of outstanding options  to acquire Nellcor Common Stock  or
P-B  Common Stock), and will have approximately 2,700 additional employees, more
than doubling the size of its work force. The Nellcor Board has concluded  that,
given  Nellcor's increased size  as a result  of the Merger,  an increase in the
authorized number of  shares under the  1994 Plan  is in the  best interests  of
Nellcor and its stockholders.

    THE  NELLCOR BOARD HAS UNANIMOUSLY APPROVED THE 1994 PLAN AMENDMENT PROPOSAL
AND UNANIMOUSLY RECOMMENDS THAT HOLDERS OF  SHARES OF NELLCOR COMMON STOCK  VOTE
"FOR" APPROVAL OF SUCH PROPOSAL.

    The essential features of the 1994 Plan are discussed below.

PURPOSE

    Nellcor,  by means of the 1994 Plan, seeks to retain the services of persons
now employed by or serving as consultants to Nellcor and to retain the  services
of persons capable of filling such positions, and to provide incentives for such
persons to exert maximum efforts for the success of Nellcor.

ADMINISTRATION

    The  1994 Plan is  administered by the  Nellcor Board or  a committee of the
Nellcor Board (the "Committee").  The 1994 Plan provides  that, for purposes  of
Section 162(m) of the Code, grants of stock awards to any "covered employee," as
such  term is defined  by Section 162(m)  (a "Covered Employee"),  shall be made
only by a subcommittee of the Committee which, in addition to meeting the  other
applicable  requirements of  the 1994  Plan, is composed  solely of  two or more
"outside directors" (the "Subcommittee") for purposes of Section 162(m). As used
herein with  respect  to  the 1994  Plan,  the  "Nellcor Board"  refers  to  the
Committee   or  the  Subcommittee  to  which  the  Nellcor  Board  may  delegate
administrative authority over the 1994 Plan as well as the Nellcor Board itself.

    The Nellcor Board  has the final  power to construe  and interpret the  1994
Plan  and the stock awards  granted under it, and,  subject to the provisions of
the 1994 Plan,  to determine,  among other matters,  the persons  to whom  stock
awards  will be granted,  and the number  of shares with  respect to which stock
awards shall be granted.

DURATION, AMENDMENT AND TERMINATION

    The Nellcor  Board may,  at any  time,  amend or  terminate the  1994  Plan,
provided,  however, that no  amendment or termination shall  impair or alter any
outstanding rights granted under  the 1994 Plan without  the written consent  of
the  grantee of such rights. Any amendment of  the 1994 Plan must be approved by
the stockholders of Nellcor if the amendment would increase the number of shares
authorized for stock awards or the maximum number of shares that may be acquired
in any single

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<PAGE>
calendar year by any individual, or modify  the 1994 Plan in any way that  would
require  stockholder  approval  under  the  requirements  of  applicable  law or
regulation. Unless sooner terminated, the 1994  Plan will terminate on July  26,
2004.

ELIGIBILITY

    Incentive  stock  options  may  be  granted  only  to  employees  (including
executive officers)  of  Nellcor  or  any affiliate.  Stock  awards  other  than
incentive  stock options may  be granted only  to employees (including executive
officers) of,  or  consultants  to,  Nellcor or  any  affiliate.  A  nonemployee
director  of  Nellcor is  not eligible  to receive  stock awards  unless certain
criteria described in the 1994 Plan are satisfied.

TERMS OF STOCK OPTIONS

    EXERCISE PRICE.  The exercise price  for any incentive stock option  granted
under  the 1994 Plan may be  not less than 100% of  the fair market value of the
Nellcor Common Stock on  the date of grant.  However, no incentive stock  option
may  be  granted  to  a  person  who, at  the  time  of  the  grant,  owns stock
constituting more than 10% of the total combined voting power of all classes  of
stock entitled to vote of Nellcor or of an affiliate ("10% Stockholder"), unless
the  exercise price is at least  110% of the fair market  value of such stock on
the date of grant and the term of the option does not exceed five years from the
grant date. The exercise  price of any nonqualified  stock option granted  under
the  1994 Plan may not  be less than 85%  of the fair market  value of the stock
subject to the option on the date of grant; provided, however, that the exercise
price of each nonqualified stock option granted to a Covered Employee shall  not
be  less than one hundred percent (100%) of the fair market value of the Nellcor
Common Stock subject to the option on the date of grant.

    In the  event of  a decline  in the  value of  Nellcor's Common  Stock,  the
Nellcor  Board has the  authority to offer optionees  the opportunity to replace
outstanding higher-priced options with new lower-priced options.

    OPTION EXERCISE.   Options granted under  the 1994 Plan  may be  immediately
exercisable  or allotted in  periodic installments as  determined by the Nellcor
Board. The Nellcor Board has  the power to accelerate  the time during which  an
option  may  be exercised.  An option  may,  but need  not, include  a provision
whereby the optionee may elect to exercise the option as to a part or all of the
shares of Nellcor Common Stock subject to the option prior to the stated vesting
dates of the option.  Any shares so purchased  from any unvested installment  or
option  may be subject to a repurchase right in favor of Nellcor or to any other
restriction the Nellcor Board determines to be appropriate.

    TERM.  The term of an option granted under the 1994 Plan generally will  not
exceed ten years.

    TERMINATION  OF OPTION.   An  option will  terminate three  months after the
optionee ceases to be an employee of or consultant to Nellcor or an affiliate of
Nellcor, except as provided in the 1994 Plan.

    NONTRANSFERABILITY.  An option may not be transferred by the optionee  other
than  by operation of law,  by will or by the  laws of descent and distribution.
During the lifetime  of an  optionee, an  option may  be exercised  only by  the
optionee or any permitted transferee.

    LIMITATION.   No  individual may be  granted options  representing more than
200,000 shares of Nellcor Common Stock in any single calendar year.

TERMS OF STOCK GRANTS, RESTRICTED STOCK GRANTS AND RESTRICTED STOCK PURCHASES

    GENERAL.  The terms of stock  grants, restricted stock grants or  restricted
stock  purchase agreements  may change  from time to  time and  may vary between
participants, but each shall include the  substance of the provisions set  forth
below:

    CONSIDERATION.    The purchase  price under  each restricted  stock purchase
agreement shall  be such  amount as  the Nellcor  Board shall  determine.  Stock
grants  and restricted  stock grants  may, at  the discretion  of the  Board, be
awarded pursuant to stock grant or restricted stock grant agreements.

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<PAGE>
    NONTRANSFERABILITY.  Rights under a stock grant agreement, restricted  stock
grant  agreement or restricted stock purchase  agreement shall not be assignable
by any participant under  the 1994 Plan, unless  such assignment is required  by
law or is expressly authorized by the terms of the applicable agreement.

    REPURCHASE  OPTION BY COMPANY.   Stock sold  or awarded under  the 1994 Plan
may, but need not, be subject to a repurchase option in favor of Nellcor.

    LIMITATION.  No individual  may be granted stock  or restricted stock or  be
granted  the right to purchase restricted stock in an amount greater than 50,000
shares of Nellcor Common Stock in any single calendar year.

    PERFORMANCE-BASED COMPENSATION.  Under the  1994 Plan, the Nellcor Board  is
authorized to grant stock awards to certain employees consisting of stock grants
or restricted stock grants which qualify as performance-based compensation under
Section  162(m)  of the  Code,  such that  the issuance  of,  or the  lapsing of
restrictions on  or  the  vesting  of, such  stock  awards  is  contingent  upon
attainment of pre-established, objective performance goals of Nellcor.

ADJUSTMENT PROVISIONS

    In  the event  of a  change in control  of Nellcor  (as defined  in the 1994
Plan), then, at  the sole  discretion of  the Nellcor  Board and  to the  extent
permitted  by applicable  law: (i)  any surviving  corporation shall  assume any
stock awards outstanding under the 1994  Plan or shall substitute similar  stock
awards  for those outstanding under  the 1994 Plan; (ii)  such stock awards will
continue in full force  and effect; or  (iii) the time  during which such  stock
awards  become  vested  or  may  be  exercised  shall  be  accelerated  and  any
outstanding unexercised rights under any stock awards shall be terminated if not
exercised prior to such event.

FEDERAL INCOME TAX CONSEQUENCES RELATING TO STOCK AWARDS

    INCENTIVE STOCK OPTIONS

    There are generally no  federal income tax consequences  to the optionee  or
Nellcor by reason of the grant or exercise of an incentive stock option.

    If  an optionee holds stock  for more than two years  from the date on which
the option is granted and more than one  year from the date on which the  shares
are transferred to the optionee upon exercise of the option, any gain or loss on
a  disposition of such stock will be  long term capital gain or loss. Generally,
if the optionee disposes of the stock  before the expiration of either of  these
holding  periods (a "disqualifying disposition"), at the time of disposition the
optionee will realize taxable  ordinary income equal to  the excess of the  fair
market  value on the date  of exercise over the  exercise price. If the optionee
disposes of  the  stock in  a  disqualifying  disposition involving  a  sale  or
exchange,  however, the optionee  will realize taxable  ordinary income equal to
the optionee's actual  gain, if  any, on the  sale or  exchange. The  optionee's
additional gain or any loss upon the disqualifying disposition will be a capital
gain  or loss  which will  be long-term or  short-term depending  on whether the
stock was held for  more than one  year. Slightly different  rules may apply  to
optionees  who acquire  stock subject to  certain repurchase options  or who are
subject to Section 16(b) of the Exchange Act.

    Upon exercise of an incentive stock  option, the excess of the stock's  fair
market  value  on the  date  of exercise  over  the option  exercise  price will
constitute an adjustment in calculating  the optionee's alternative minimum  tax
liability, if any.

    To  the  extent  the optionee  recognizes  ordinary  income by  reason  of a
disqualifying disposition, Nellcor will be entitled (subject to the  requirement
of  reasonableness and perhaps, in the future, the satisfaction of a withholding
obligation) to a  corresponding business expense  deduction in the  tax year  in
which the disposition occurs.

                                       75
<PAGE>
    NONQUALIFIED STOCK OPTIONS

    There generally are no tax consequences to the optionee or Nellcor by reason
of  the grant of  a nonqualified stock  option. Upon exercise  of a nonqualified
stock option normally the optionee will recognize taxable ordinary income  equal
to  the excess of the stock's fair market value on the date of exercise over the
exercise  price.  Subject   to  the  requirement   of  reasonableness  and   the
satisfaction  of  any  withholding obligation,  Nellcor  will be  entitled  to a
business expense deduction equal to the taxable ordinary income realized by  the
optionee.  Upon disposition of stock, the optionee will recognize a capital gain
or loss equal to  the difference between  the selling price and  the sum of  the
amount  paid for such stock  plus any amount recognized  as ordinary income upon
exercise of the option. Such gain or  loss will be long or short-term  depending
on  whether the stock was held for  more than one year. Slightly different rules
may apply to optionees who acquire  stock subject to certain repurchase  options
or who are subject to Section 16(b) of the Exchange Act.

    STOCK GRANTS, RESTRICTED STOCK GRANTS AND RESTRICTED STOCK PURCHASES

    Generally, a recipient of stock under the 1994 Plan would recognize ordinary
income  equal to  the difference between  the market  value of the  stock on the
grant or purchase date and any amount paid or required to be paid for the stock.
If the stock is  restricted and subject  to vesting, then  the recipient of  the
stock  would recognize ordinary  income as the restrictions  are removed and the
stock vests. On each vesting date, the recipient would recognize ordinary income
equal to the difference  between the fair  market value of  the shares of  stock
that have vested on such date and any amount paid or required to be paid for the
shares  of stock. The recipient  of the stock would  not recognize any income to
the extent the rights to the stock  have not vested. A recipient of stock  under
the  1994 Plan, however,  may make an  election under Section  83(b) of the Code
within 30 days  of the stock  award to be  taxed at the  grant date at  ordinary
income rates on the difference between the fair market value of the stock on the
grant  or purchase date and any amount paid by the recipient for the stock. If a
Section 83(b)  election is  made  the recipient  will  not recognize  income  on
subsequent vesting of the award. However, no loss or deduction will be permitted
the recipient if the restricted stock is forfeited.

    Subject  to the  requirement of reasonableness  and the  satisfaction of any
withholding obligation, Nellcor will be entitled to a business expense deduction
equal to the taxable ordinary income realized by the recipient.

    Upon disposition of stock,  the recipient will recognize  a capital gain  or
loss equal to the difference between the selling price and the sum of the amount
paid  for such stock plus any amount recognized as ordinary income. Such gain or
loss will be long-  or short-term depending  on whether the  stock was held  for
more than one year.

    OTHER TAX CONSEQUENCES

    The foregoing discussion is not a complete description of the federal income
tax  aspects  of  stock  awards  granted  under  the  1994  Plan.  In  addition,
administrative and judicial  interpretations of the  application of the  federal
income tax laws are subject to change. Furthermore, no information is given with
respect to state or local taxes that may be applicable or any stock awards other
than options. Participants in the 1994 Plan who are residents of or are employed
in  a  country  other than  the  United States  may  be subject  to  taxation in
accordance with the tax  laws of that  particular country in  addition to or  in
lieu of United States federal income taxes.

NEW PLAN BENEFITS

    Because  stock awards under the 1994 Plan are discretionary, the benefits to
be received under the 1994 Plan by any director, officer or employee of  Nellcor
cannot presently be determined.

                                       76
<PAGE>
                     COMPENSATION OF DIRECTORS AND CERTAIN
                         EXECUTIVE OFFICERS OF NELLCOR

GENERAL

    This   section  of   the  Proxy  Statement/Prospectus   sets  forth  certain
information pertaining  to  compensation  of  the  Chief  Executive  Officer  of
Nellcor,  Nellcor's four most  highly compensated executive  officers other than
the  Chief  Executive  Officer  during  its  fiscal  year  ended  July  3,  1994
("Nellcor's Fiscal 1994") and two individuals who would have been among the four
other most highly compensated executive officers but for the fact that they were
not serving as executive officers of Nellcor at the end of Nellcor's Fiscal 1994
(collectively,  the "Nellcor Named Executive  Officers"), as well as information
pertaining to the compensation of members of the Nellcor Board.

                           SUMMARY COMPENSATION TABLE

<TABLE>
<CAPTION>
                                                                                                  LONG-TERM
                                                                                                COMPENSATION
                                                                                                   AWARDS
                                                                ANNUAL COMPENSATION         ---------------------
                                                           ------------------------------   SECURITIES UNDERLYING      ALL OTHER
NAME AND PRINCIPAL POSITION                                YEAR  SALARY ($)    BONUS ($)         OPTIONS (#)        COMPENSATION (1)
- ---------------------------------------------------------  ----  ----------   -----------   ---------------------   ---------------
<S>                                                        <C>   <C>          <C>           <C>                     <C>
C. Raymond Larkin, Jr....................................  1994   $302,171    $178,000              54,000              $     0
 President and Chief Executive                             1993    284,530     199,171              50,000                    0
 Officer                                                   1992    266,641     232,837             100,000                    0
David B. Swedlow, M.D....................................  1994   $253,920    $102,025              20,000              $   800
 Vice President, Medical Affairs                           1993    240,128     100,800              22,500                  800
 and Technology Development                                1992    217,923     124,327              20,000                  750
Michael P. Downey........................................  1994   $181,001    $ 73,347              20,000              $   800
 Executive Vice President,                                 1993    168,840      81,043              17,500                  800
 Chief Financial Officer                                   1992    155,509      86,745              20,000                  750
Laureen DeBuono..........................................  1994   $169,478    $ 75,106              20,000              $   800
 Executive Vice President,                                 1993    150,000      73,200                   0                  400
 Human Resources, General                                  1992     31,731           0              40,000               29,000
 Counsel and Secretary
Keith M. Serzen (4)......................................  1994   $170,820    $ 62,768              20,000              $   800
                                                           1993    159,000      65,190              17,500                  800
                                                           1992    147,118      90,700              20,000                  750
David L. Schlotterbeck (5)...............................  1994   $240,793    $ 93,902              37,000              $ 6,410
                                                           1993    236,707     141,750              36,000                7,164
                                                           1992    225,400     154,350(2)                0                  400
Patricia E. Bashaw (6)...................................  1994   $162,735    $ 68,243              18,000              $ 3,120
                                                           1993    162,640      62,454              17,500                3,901
                                                           1992    155,509      77,100(3)           20,000                  750
<FN>
- ------------------------------
Notes:

(1)  Amounts  reported  as  All   Other  Compensation  represent  the   matching
     contributions  paid by Nellcor to the  named executive officers pursuant to
     the Voluntary Investment Plus Plan,  as amended and restated ("VIP  Plan"),
     described  below,  except that  (i) with  regard to  Ms. Bashaw,  All Other
     Compensation includes for each of fiscal  years 1994 and 1993, $800 in  VIP
     Plan  matching contributions and $2,320 in Nellcor's fiscal 1994 and $3,101
     in fiscal year  1993 as interest  paid on compensation  deferred under  the
     terms of the Nellcor Incorporated Deferred Compensation Plan (the "Deferred
     Plan")  described below  under "--  Deferred Compensation  Plan," (ii) with
     regard to Mr. Schlotterbeck,  All Other Compensation  includes for each  of
     Nellcor's   fiscal  years  1994  and  1993,   $800  in  VIP  Plan  matching
     contributions and $5,610 in Nellcor's  fiscal 1994 and $6,364 in  Nellcor's
     fiscal  year  1993  as interest  paid  on compensation  deferred  under the
     Deferred Plan and (iii) with regard to Ms. DeBuono, All Other  Compensation
     in  fiscal year 1992  consists of $29,000  paid upon her  acceptance of her
     current position with Nellcor.
</TABLE>

                                       77
<PAGE>
<TABLE>
<S>  <C>
(2)  Includes $123,480 deferred under the terms of the Deferred Plan.

(3)  Includes $51,063 deferred under the terms of the Deferred Plan.

(4)  Mr. Serzen  resigned  from his  position  as Vice  President,  Sensors  and
     Monitoring Systems of Nellcor effective January 27, 1995.

(5)  Mr.  Schlotterbeck resigned from  his position as  Executive Vice President
     and Chief Operating Officer  of Nellcor effective June  17, 1994. Upon  Mr.
     Schlotterbeck's  resignation  from Nellcor,  he  was paid  $133,395.80, the
     remaining balance (deferred compensation plus accrued but unpaid  interest)
     in  Mr. Schlotterbeck's  account under the  Deferred Plan.  See "-- Certain
     Transactions."

(6)  Ms. Bashaw resigned from her position as Vice President, Corporate Services
     of Nellcor  effective June  15, 1994.  Upon Ms.  Bashaw's resignation  from
     Nellcor,   she  was  paid  $55,163.86,   the  remaining  balance  (deferred
     compensation plus  accrued but  unpaid interest)  in Ms.  Bashaw's  account
     under the Deferred Plan. See "-- Certain Transactions."
</TABLE>

OTHER COMPENSATION

    Nellcor  has  in  effect  compensation  plans  providing  various  forms  of
benefits, payable in cash or deferred  for several years (or until  retirement).
Executive  officers are  eligible to participate  in certain of  these plans, as
discussed below.  The  cash  bonus  plan for  executive  officers  is  currently
administered  by the Nominating and Compensation Committee of the Nellcor Board;
all other  compensation  plans  are  currently  administered  by  the  Board  of
Directors  with the assistance of the Executive Vice President, Human Resources,
General Counsel and Secretary.

EMPLOYEE STOCK OPTION PLANS

    As of July  3, 1994,  Nellcor had  options outstanding  under the  following
three  plans: its 1982  Incentive Stock Option  Plan (the "ISO  Plan"), its 1985
Equity Incentive Plan (the "1985 Plan")  and its 1991 Equity Incentive Plan,  as
amended  (the "1991 Plan"). Subsequent to July 3, 1994, Nellcor adopted the 1994
Plan, which was approved by Nellcor's  stockholders at the 1994 annual  meeting.
Shares  remaining available for issuance under the ISO Plan and the 1985 Plan at
the time of such plans' termination  by the stockholders in October 1991  became
available  for issuance  under the  1991 Plan.  Early in  Nellcor's Fiscal 1994,
Nellcor commenced a  Limited Stock  Repurchase Program  (the "Limited  Program")
pursuant to which Nellcor repurchases shares of its Common Stock to mitigate the
dilutive  effects of Nellcor's  stock option plans, including  the 1991 Plan and
the 1994 Plan.  Repurchases made under  the Limited Program  are on a  recurring
basis  to the extent that stock options are exercised during the fiscal year and
totaled 522,500 shares as of the end of Nellcor's Fiscal 1994.

    The 1991 Plan and the 1994 Plan are currently administered by the Nominating
and Compensation  Committee  of the  Nellcor  Board with  respect  to  executive
officers  and by the Board with respect  to other key employees and consultants.
The Nellcor Board or the Nominating and Compensation Committee, as the case  may
be,  has the sole discretion to  determine the executive officers, key employees
and consultants to whom options may be granted, the number of shares subject  to
such options and the type and term of the options.

    The option exercise price of an incentive stock option granted under the ISO
Plan,  the 1991 Plan and the 1994 Plan must  be at least 100% of the fair market
value of Nellcor's Common Stock  on the date of  grant, and the option  exercise
price  of a nonqualified stock option granted under the 1985 Plan, the 1991 Plan
and the 1994 Plan  must be at least  85% of the fair  market value of  Nellcor's
Common Stock on the date of grant. It should be noted, however, that all options
granted  to  date pursuant  to the  plans described  above have  option exercise
prices that are no less than 100%  of the fair market value of Nellcor's  Common
Stock  on the date of grant  and that none may be  exercised more than ten years
from the date of  grant. To date,  no options have been  granted under the  1994
Plan.

                                       78
<PAGE>
    The  following table contains information  concerning stock option grants in
Nellcor's Fiscal 1994 to the named executive officers:

                     OPTION GRANTS IN NELLCOR'S FISCAL 1994
<TABLE>
<CAPTION>
                                                                    INDIVIDUAL GRANTS
                               --------------------------------------------------------------------------------------------
                                NUMBER OF SECURITIES     % OF TOTAL OPTIONS/SARS
                               UNDERLYING OPTIONS/SARS   GRANTED TO EMPLOYEES IN   EXERCISE OF BASE PRICE
 NAME                              GRANTED (#)(1)           FISCAL YEAR 1994             ($/SH)(2)          EXPIRATION DATE
 ----------------------------  -----------------------   -----------------------   ----------------------   ---------------
 <S>                           <C>                       <C>                       <C>                      <C>
 C. Raymond Larkin, Jr.......          54,000                        7.52                  $   23.25           07-27-03
 Laureen DeBuono.............          20,000                        2.78                      23.25           07-27-03
 Michael P. Downey...........          20,000                        2.78                      23.25           07-27-03
 Keith M. Serzen (4).........          20,000                        2.78                      23.25           07-27-03
 David B. Swedlow, M.D.......          20,000                        2.78                      23.25           07-27-03
 Patricia E. Bashaw (5)......          18,000                        2.50                      23.25           07-27-03
 David L. Schlotterbeck
  (6)........................          37,000                        5.15                      23.25           07-27-03

<CAPTION>

                               POTENTIAL REALIZABLE
                                     VALUE AT
                               ASSUMED ANNUAL RATES
                                     OF STOCK
                                PRICE APPRECIATION
                                 FOR OPTION TERM
                               --------------------
 NAME                          5%($)(3)  10%($)(3)
 ----------------------------  --------  ----------
 <S>                           <C>       <C>
 C. Raymond Larkin, Jr.......  $789,304  $2,000,093
 Laureen DeBuono.............   292,335     740,775
 Michael P. Downey...........   292,335     740,775
 Keith M. Serzen (4).........   292,335     740,775
 David B. Swedlow, M.D.......   292,335     740,775
 Patricia E. Bashaw (5)......   263,101     666,698
 David L. Schlotterbeck
  (6)........................   540,819   1,370,434
<FN>
- ------------------------------
Notes:

(1)  These stock options were granted to each of the named executive officers on
     July 28,  1993. The  grants of  stock  options were  made pursuant  to  the
     standard  terms of  the 1991 Plan  as described above.  These stock options
     have a ten-year  term, vest on  a quarterly basis  over a four-year  period
     beginning  the date of grant and have  exercise prices equal to 100% of the
     fair market value of Nellcor Common Stock on the date of grant. Nellcor has
     not granted  Stock Appreciation  Rights  ("SARs") pursuant  to any  of  its
     employee  stock option  plans to any  past or present  employee of Nellcor,
     including any executive officer.

(2)  The exercise price may be paid in  cash, in shares of Nellcor Common  Stock
     valued  at fair  market value  on the exercise  date or  through a cashless
     exercise involving a same-day sale of the purchased shares. The  Nominating
     and  Compensation Committee of the Nellcor Board also has the discretion to
     reprice outstanding  options by  canceling  them and  granting  replacement
     options  with an  exercise price  equal to the  lower fair  market value of
     Nellcor Common Stock on the re-grant date. Nellcor to date has not repriced
     options granted pursuant to its employee stock option plans.

(3)  These columns reflect the potential  realizable value of each stock  option
     grant assuming that the market value of Nellcor Common Stock appreciates at
     5% and 10% annually from the date of grant over the term of the option. The
     potential  values of the options with an exercise price of $23.25 reflect a
     42% increase (@ 5%)  and a 126%  increase (@ 10%) in  the value of  Nellcor
     Common  Stock over  the 1994 fiscal  year-end market price  of $26.625, the
     average of the high and low prices  as reported by Nasdaq on July 1,  1994.
     There  is no  assurance that the  actual stock price  appreciation over the
     term of the option will be at the assumed 5% or 10% levels or at any  other
     level.  Unless the market price  of the stock does  in fact appreciate over
     the option term, no value will be realized from option grants.

(4)  Mr. Serzen  resigned  from his  position  as Vice  President,  Sensors  and
     Monitoring Systems of Nellcor effective January 27, 1995.

(5)  Ms. Bashaw resigned from her position as Vice President, Corporate Services
     of Nellcor effective June 15, 1994.

(6)  Mr.  Schlotterbeck resigned from  his position as  Executive Vice President
     and Chief Operating Officer effective June 17, 1994.
</TABLE>

                                       79
<PAGE>
STOCK OPTION EXERCISES AND HOLDINGS

    The  following table provides  information concerning the  exercise of stock
options by the  named executive officers  during Nellcor's Fiscal  1994 and  the
unexercised  options held  by such  officers as of  the end  of Nellcor's Fiscal
1994.

              AGGREGATED OPTION EXERCISES IN NELLCOR'S FISCAL 1994
                       AND FISCAL YEAR-END OPTION VALUES

<TABLE>
<CAPTION>
                                                                      NUMBER OF SECURITIES
                                                                     UNDERLYING UNEXERCISED         VALUE OF UNEXERCISED IN-
                                                                  OPTIONS/SARS AT FISCAL YEAR      THE-MONEY OPTIONS/SARS AT
                                   SHARES ACQUIRED     VALUE               END (#)(1)                FISCAL YEAR END ($)(2)
                                     ON EXERCISE     REALIZED    ------------------------------  ------------------------------
NAME                                     (#)            ($)       EXERCISABLE    UNEXERCISABLE    EXERCISABLE    UNEXERCISABLE
- ---------------------------------  ---------------  -----------  -------------  ---------------  -------------  ---------------
<S>                                <C>              <C>          <C>            <C>              <C>            <C>
C. Raymond Larkin, Jr............        75,500      1,209,875       157,000         107,000      $ 1,115,719      $ 364,781
Laureen DeBuono..................             0              0        23,750          36,250           32,187         72,812
Michael P. Downey................        14,000        238,150        64,531          32,969          573,047         95,703
Keith M. Serzen (3)..............        21,000        364,875        34,531          32,969          205,547         95,703
David B. Swedlow, M.D............        15,000        253,125        41,094          36,406          263,561         99,564
Patricia E. Bashaw (4)...........        35,000        590,625        46,031          24,469          309,094         47,531
David L. Schlotterbeck (5).......         6,500         53,000        61,188               0          330,548              0
<FN>
- ------------------------------
Notes:

(1)  Nellcor has not granted SARs pursuant  to any of its employee stock  option
     plans  to any past or present  employee of Nellcor, including any executive
     officer.

(2)  Amounts in this column are calculated using the per share closing price  on
     Nasdaq of Nellcor Common Stock at the end of Nellcor's Fiscal 1994 ($26.50)
     less the exercise price.

(3)  Mr.  Serzen  resigned  from his  position  as Vice  President,  Sensors and
     Monitoring Systems of Nellcor effective January 27, 1995.

(4)  Ms. Bashaw resigned from her position as Vice President, Corporate Services
     of Nellcor effective June 15, 1994.

(5)  Mr. Schlotterbeck resigned  from his position  as Executive Vice  President
     and Chief Operating Officer of Nellcor effective June 17, 1994.
</TABLE>

VOLUNTARY INVESTMENT PLUS PLAN

    Pursuant  to  the Nellcor  Voluntary Investment  Plus  Plan, as  amended and
restated (the  "VIP  Plan"),  employees of  Nellcor  and  certain  subsidiaries,
including   executive  officers,  approved  by   the  Nellcor  Board  may  defer
compensation for income  tax purposes under  Sections 401(a) and  401(k) of  the
Code.  All employees of Nellcor who regularly work 30 hours or more per week are
eligible to participate  in the VIP  Plan at the  beginning of their  employment
with  Nellcor. In addition,  all employees who  complete 1,000 hours  or more in
their first 12 months of service or in any subsequent calendar year are eligible
to participate in the  VIP Plan. As  of July 3, 1994,  736 employees other  than
executive  officers  were  participating in  the  VIP Plan.  Subject  to certain
limitations on "highly compensated employees" (as defined by the Code), eligible
participants may  contribute  to  their accounts,  through  payroll  deductions,
between  1% and 10% of their compensation on a "pre-tax" basis. Compensation for
purposes of the  VIP Plan includes  base salary, cash  profit sharing,  bonuses,
commissions   and  overtime  pay.  Pursuant  to  Section  401(k)  of  the  Code,
participants will not be taxed on  the pre-tax amounts they contribute to  their
accounts  until  the  accounts  are  distributed  on  death,  disability, normal
retirement or other termination of  employment. Contributed amounts may also  be
withdrawn  from  the  VIP  Plan  in  cases  of  demonstrable  hardship  or  if a
participant has attained at least 59 years of age. All contributions are held by
a trustee and participants are able  to direct the investment of their  accounts
among various investment alternatives.

    Nellcor  provides matching contributions equal to 100% of each participant's
contribution, up  to  $400 semi-annually.  Nellcor  contributions to  the  named
executive  officers for each of the 1994,  1993 and 1992 fiscal years of Nellcor
are included in All Other Compensation listed on the Summary Compensation  Table
above.

                                       80
<PAGE>
DEFERRED COMPENSATION PLAN

    Nellcor  has established a deferred compensation plan for executive officers
and director-level employees that was approved by the Nellcor Board on July  16,
1992   ("the  Deferred  Plan").  Eligibility   for  participation  is  based  on
achievement of a  certain employment level  at Nellcor. Under  the terms of  the
Deferred  Plan, an eligible  participant may elect  to defer all  or part of the
participant's annual base salary and/or bonus award. Amounts deferred under  the
Deferred   Plan  are  credited  to  a  separate  bookkeeping  account  for  each
participant and are commingled with the  general assets of Nellcor. Interest  on
the  amounts deferred is calculated on a  quarterly basis using an interest rate
equal to  the average  pre-tax rate  earned on  Nellcor's Marketable  Securities
Portfolio  during  the  same  quarter.  This  rate,  published  monthly  by  the
Marketable Securities Portfolio Manager, will be weighted to achieve a quarterly
average pre-tax rate. The  time and method of  payment of deferred  compensation
and  other terms and conditions are set forth in deferred compensation elections
made prior to deferral by each participant. The Deferred Plan is not  separately
funded,  and the undistributed  balance of deferred  compensation constitutes an
unsecured contractual obligation  of Nellcor to  the participants in  accordance
with  the  terms  of the  plan.  Deferred  compensation by  the  named executive
officers for each  of the 1994,  1993 and 1992  fiscal years of  Nellcor is  set
forth in the Summary Compensation Table above.

CERTAIN TRANSACTIONS

    Effective  December  1,  1993,  Robert  M. Johnson  ceased  to  be  the Vice
President and General Manager  of Nellcor's Perinatal  Division. Pursuant to  an
agreement entered into by Nellcor and Mr. Johnson, Nellcor agreed to (i) pay Mr.
Johnson a severance payment of $157,446 in three installments, the last of which
is payable on November 30, 1994, (ii) forgive a promissory note from Mr. Johnson
to  Nellcor in the aggregate principal amount of $15,000 and (iii) reimburse Mr.
Johnson for COBRA  insurance premiums for  12 months after  his separation  from
Nellcor.  Under  the terms  of a  consulting agreement  between Nellcor  and Mr.
Johnson, Mr.  Johnson serves  as a  consultant to  Nellcor's Perinatal  Division
until  March 1,  1995. In  consideration of  Mr. Johnson's  consulting services,
Nellcor agreed to extend until  March 1, 1995 the  time period during which  Mr.
Johnson may exercise certain vested and exercisable stock options held by him as
of December 1, 1993.

    Patricia  Bashaw, former  Vice President,  Corporate Services,  left Nellcor
effective June 15,  1994. In  connection with  her departure,  Nellcor paid  Ms.
Bashaw a lump-sum payment of $170,609. Nellcor also agreed to (i) pay Ms. Bashaw
a  bonus of $68,243  for her services  to Nellcor during  fiscal year 1994, (ii)
reimburse her for COBRA insurance premiums for 18 months beginning July 1,  1994
and  (iii) accelerate the vesting of options to purchase 8,125 shares of Nellcor
Common Stock.  Nellcor  and  Ms.  Bashaw entered  into  a  consulting  agreement
pursuant  to  which  she would  provide  consulting  services to  Nellcor  on an
as-needed basis until June  15, 1996. Ms.  Bashaw is to be  paid $1,500 per  day
worked  for  her consulting  services. Nellcor  agreed  that any  unvested stock
options held by Ms. Bashaw would  continue to vest during the consulting  period
and  that the time period during which Ms. Bashaw may exercise her stock options
would extend until the end of the consulting period.

    In connection  with  David  Schlotterbeck's resignation  as  Executive  Vice
President  and  Chief Operating  Officer of  Nellcor,  effective June  17, 1994,
Nellcor agreed to pay Mr. Schlotterbeck a  bonus of $93,902 for his services  to
Nellcor  during fiscal year  1994. Nellcor also extended  from September 1994 to
November 1994 the  period of time  during which Mr.  Schlotterbeck may  exercise
vested and exercisable stock options held by him as of the effective date of his
resignation.

    Effective  July  3, 1994,  Julio Guardado  ceased to  be Vice  President and
General Manager  of  Nellcor's Monitoring  Systems  Division. Nellcor  paid  Mr.
Guardado  a lump sum payment of $162,180. Nellcor also paid Mr. Guardado a bonus
of $48,654 for his  services to Nellcor  during fiscal year  1994 and agreed  to
reimburse  Mr. Guardado  for COBRA  insurance premiums  for 12  months beginning
August 1, 1994.  Nellcor also extended  from October 1994  to November 1994  the
period  of time  during which Mr.  Guardado may exercise  vested and exercisable
stock options  held by  him  as of  the effective  date  of his  departure  from
Nellcor.

                                       81
<PAGE>
INDEBTEDNESS OF MANAGEMENT

    The  following table sets forth information  with regard to promissory notes
from any person who was an executive officer  of Nellcor as of July 3, 1994  who
have  had amounts of  $60,000 or more  outstanding at any  time during Nellcor's
Fiscal 1994. In general, the promissory notes have terms of three or four  years
and  bear interest at the adjusted federal rate ("AFR") in effect on the date of
the loan. Certain promissory notes allow quarterly or annual forgiveness of  the
principal and/or interest on the note.

<TABLE>
<CAPTION>
                                                                                                LARGEST AMOUNT OF
                                                                            PRINCIPAL AMOUNT        PRINCIPAL
                                                                             OUTSTANDING AT    OUTSTANDING DURING
NAME OF INDIVIDUAL                                       DATE OF NOTE        AUGUST 19, 1994      7/5/93-7/3/94
- --------------------------------------------------  ----------------------  -----------------  -------------------
<S>                                                 <C>                     <C>                <C>
David J. Illingworth .............................       February 18, 1993    $     250,000        $   250,000
 Vice President, Field Operations and Service (1)
<FN>
- ------------------------
Notes:

(1)  Mr.  Illingworth, Nellcor's  Vice President, Field  Operations and Service,
     joined Nellcor in November 1992. Pursuant to the terms of his offer letter,
     Mr. Illingworth received a sign-on bonus of $20,000, a guaranteed bonus  of
     $60,000  payable in two  installments ($30,000 paid on  the initial date of
     employment; $30,000 paid on March 1, 1993) in lieu of a 1992 bonus from his
     former employer  forfeited by  Mr. Illingworth,  an interest-free  loan  of
     $7,000 with principal forgiven over four years at the rate of 25% per year,
     and   an  interest-bearing  loan  of  $250,000  with  which  to  repay  his
     outstanding relocation  loan with  his former  employer. Mr.  Illingworth's
     loan  with  Nellcor  is secured  by  his  primary residence  with  a second
     mortgage. Payment  of interest  on the  loan, which  accrues at  an  annual
     interest  rate of 7.64%,  is to be  made in 20  semi-annual installments of
     $9,375 each over  a period  of 10  years, with  the first  payment made  on
     August  18, 1993. An amount equal to each interest installment, as made, is
     added to Mr. Illingworth's base  salary compensation. The principal  amount
     of  the  loan  is  due upon  the  earlier  of the  sale  of  the residence,
     termination of employment with Nellcor, or February 18, 2003.
</TABLE>

COMPENSATION OF DIRECTORS

    Each non-employee Nellcor director  received a retainer  fee of $10,000  for
Nellcor's  Fiscal 1994 to  serve on the Nellcor  Board plus a  fee of $1,500 for
each meeting of  the Nellcor Board  attended and $1,000  for each Nellcor  Board
committee meeting attended which was not held on the same day as a Nellcor Board
meeting.  Beginning  fiscal  year  1995,  the  chairperson  of  a  Nellcor Board
committee meeting  received an  additional $1,000  for each  committee  meeting.
Nellcor  does not pay directors' fees to directors who are employees of Nellcor.
In addition to board  retainer and attendance fees,  Messrs. Glaser and  Grafton
received  $948 and  $37,958, respectively,  in consulting  fees during Nellcor's
Fiscal 1994 pursuant  to consulting  agreements with Nellcor  which provide  for
compensation  at $138 and  $150 per hour,  respectively, for consulting services
rendered to Nellcor.

    Non-employee directors also  receive non-discretionary  stock option  grants
under  Nellcor's 1988 Stock  Option Plan for  Non-Employee Directors, as amended
(the "Directors' Plan"). In May 1994,  the Nellcor Board amended the  Directors'
Plan  to reduce the stock option  grants to non-employee directors. Effective in
Nellcor's fiscal  year 1995,  each non-employee  director (i)  upon joining  the
Nellcor  Board for the first time, will be automatically granted an option under
the Directors' Plan to purchase 10,000  shares of Nellcor Common Stock,  vesting
over  four years from the  date of grant, 25%  at the end of  the first year and
6.25% per quarter  thereafter, and  (ii) at the  beginning of  each fiscal  year
(beginning  fiscal year 1995), will be automatically granted an option under the
Directors' Plan  to purchase  5,000  shares, vesting  over  one year.  Prior  to
amendment,  the Directors'  Plan provided  for a  non-discretionary stock option
grant of 20,000 shares  upon a non-employee director's  initial election to  the
Nellcor Board and thereafter yearly stock option grants of 10,000 shares.

                                       82
<PAGE>
    The  following table sets forth as to all current non-employee directors for
Nellcor's Fiscal 1994 (i) the number  of shares of Nellcor Common Stock  subject
to  options granted under the Directors' Plan and the weighted average per share
exercise price for such options and (ii) the number of shares of Nellcor  Common
Stock  acquired and  the net  value realized  (fair market  value of  the shares
acquired on the date of exercise less  the exercise price) upon the exercise  of
options.

<TABLE>
<CAPTION>
                                                                             FISCAL YEAR 1994
                                                         ---------------------------------------------------------
                                                                OPTIONS GRANTED             OPTIONS EXERCISED
                                                         -----------------------------  --------------------------
                                                          NUMBER OF                      NUMBER OF     NET VALUE
NAME                                                       SHARES      EXERCISE PRICE     SHARES     REALIZED (1)
- -------------------------------------------------------  -----------  ----------------  -----------  -------------
<S>                                                      <C>          <C>               <C>          <C>
Robert J. Glaser, M.D..................................      10,000      $   23.50               0    $         0
Frederick M. Grafton...................................      10,000          23.50           5,000         90,625
Donald L. Hammond......................................      10,000          23.50               0              0
Walter J. McNerney.....................................      10,000          23.50               0              0
Edwin E. van Bronkhorst................................      10,000          23.50               0              0
<FN>
- ------------------------
Notes:

(1)  Equal  to  the fair  market value  of  the shares  of Nellcor  Common Stock
     acquired on the date the options were exercised less the exercise price.
</TABLE>

    The per share closing price of Nellcor Common Stock as reported by Nasdaq on
July 1, 1994 was $26.50.

NOMINATING AND COMPENSATION COMMITTEE INTERLOCKS AND INSIDER PARTICIPATION

    There are  no  Nominating  and  Compensation  Committee  interlocks  between
Nellcor  and other  entities involving any  of Nellcor's  executive officers and
members of the Nellcor Board who  serve as executive officers of such  entities,
and  no member  of the  Nominating and  Compensation Committee  is a  present or
former officer or employee of Nellcor.

                                       83
<PAGE>
                   BENEFICIAL OWNERS OF NELLCOR COMMON STOCK

    The following table sets forth, as of June 30, 1995, the beneficial holdings
of  Nellcor Common Stock  (Nellcor's only outstanding  voting securities) by (i)
each person  known by  Nellcor to  be the  beneficial owner  of more  than  five
percent  of  the  Nellcor  Common  Stock, (ii)  each  of  the  five non-employee
directors, (iii) the President and Chief  Executive Officer (also a director  of
Nellcor  and hereinafter  referred to  as the  Chief Executive  Officer) and the
other  named  executive  officers  listed  in  the  Summary  Compensation  Table
appearing  above in this Proxy Statement/Prospectus,  and (iv) all directors and
executive officers of Nellcor as a group.

<TABLE>
<CAPTION>
                                                               AMOUNT AND NATURE OF
                                                                    BENEFICIAL
NAME OF BENEFICIAL OWNER                                           OWNERSHIP (1)       PERCENT OF CLASS
- -------------------------------------------------------------  ---------------------  -------------------
<S>                                                            <C>                    <C>
FMR Corp.
 82 Devonshire Street
 Boston, MA 02109 (2)........................................          1,798,500              10.84%
Laureen DeBuono, Executive Vice President, Human Resources,
 General Counsel and Secretary...............................             28,850                .17%
Michael P. Downey, Executive Vice President,
 Chief Financial Officer.....................................             59,125                .35%
Robert J. Glaser, M.D., Director.............................             31,500                .19%
Frederick M. Grafton, Director...............................             35,000                .21%
Donald L. Hammond, Director..................................             40,000                .24%
C. Raymond Larkin, Jr., Director, President and Chief
 Executive Officer...........................................            338,784               2.03%
Walter J. McNerney, Director.................................             55,300                .33%
Keith M. Serzen (4)(7).......................................            *                     *
David B. Swedlow, M.D., Vice President, Medical Affairs and
 Technology Development......................................            100,250                .60%
Edwin E. van Bronkhorst, Director............................             56,000                .34%
Patricia E. Bashaw (5)(7)....................................             62,094                .37%
David L. Schlotterbeck (6)(7)................................              1,500                .01%
All Directors and Executive Officers
 as a Group (15 persons) (3).................................            846,334               5.07%
<FN>
- ------------------------
Notes:
(1)  Each director and  named executive  officer listed  in the  table has  sole
     voting  and sole  dispositive power. Includes  for each  director and named
     executive officer listed in the table: (i) in the cases of Messrs.  Glaser,
     Grafton,  Hammond, McNerney and van Bronkhorst, options to purchase 27,500,
     30,000,  25,000,  55,000  and  25,000  shares  of  Nellcor  Common   Stock,
     respectively,  and (ii) in the cases of Ms. Bashaw, Ms. DeBuono and Messrs.
     Downey, Larkin,  Schlotterbeck, Serzen  and  Swedlow, options  to  purchase
     30,094,  28,250, 58,125, 237,750, 0, 0  and 66,250 shares of Nellcor Common
     Stock, respectively, all of which options are exercisable within 60 days of
     June 30, 1995. Also includes for all directors and executive officers as  a
     group  options to purchase 654,000 shares of Nellcor Common Stock which are
     exercisable within 60 days of June 30, 1995.
(2)  Information regarding FMR  Corp.'s beneficial ownership  of Nellcor  Common
     Stock  has been obtained from the Schedule  13G filed by FMR Corp. with the
     Commission on May 9, 1995.
(3)  Executive Officers  include  the  Chief  Executive  Officer  and  all  Vice
     Presidents of Nellcor.
</TABLE>

                                       84
<PAGE>
<TABLE>
<S>  <C>
(4)  Mr.  Serzen  resigned  from his  position  as Vice  President,  Sensors and
     Monitoring Systems of Nellcor effective January 27, 1995.
(5)  Ms. Bashaw resigned from her position as Vice President, Corporate Services
     of Nellcor effective June 15, 1994.
(6)  Mr. Schlotterbeck resigned  from his position  as Executive Vice  President
     and Chief Operating Officer of Nellcor effective June 17, 1994.
(7)  Information regarding the number of shares of Nellcor Common Stock owned by
     these  individuals, none of whom is presently employed by Nellcor, has been
     obtained from information  provided by  such individuals to  Nellcor as  of
     August 26, 1994.
</TABLE>

                    DESCRIPTION OF CAPITAL STOCK OF NELLCOR

AUTHORIZED CAPITAL STOCK

    Nellcor's   authorized  capital  stock   presently  consists  of  50,000,000
authorized shares  of Nellcor  Common  Stock, $0.001  par value,  and  5,000,000
authorized shares of preferred stock (the "Nellcor Preferred Stock"), $0.001 par
value.  The  Merger will  not result  in  an increase  or decrease  of Nellcor's
authorized capital.

NELLCOR COMMON STOCK

    As of July 19, 1995, 16,727,723  shares of Nellcor Common Stock were  issued
and  outstanding, stock  options to acquire  2,269,789 shares  of Nellcor Common
Stock were outstanding under all stock option plans of Nellcor.

    The holders of Nellcor Common Stock are entitled to one vote for each  share
on  all matters voted on  by the stockholders. At  all elections of directors of
Nellcor, each holder of  Nellcor Common Stock  is entitled to  as many votes  as
shall  equal the  number of  votes which he  would be  entitled to  cast for the
election of directors with respect to  his shares of Common Stock multiplied  by
the  number of directors to be  elected by him, and such  holder may cast all of
such votes for a single director or  may distribute them among the number to  be
voted  for or for  any two or more  of them. Subject to  preferences that may be
applicable to any outstanding Nellcor Preferred Stock, holders of Nellcor Common
Stock are entitled to receive ratably such  dividends as may be declared by  the
Nellcor  Board  out of  funds  legally available  therefor.  In the  event  of a
liquidation, dissolution or  winding up  of Nellcor, holders  of Nellcor  Common
Stock  are entitled to share  ratably in all assets  remaining after payments to
all creditors and  payments required to  be made in  respect of any  outstanding
Nellcor  Preferred Stock.  Holders of  Nellcor Common  Stock have  no preemptive
rights and have no rights to convert  their Nellcor Common Stock into any  other
securities.

NELLCOR PREFERRED STOCK

    The  Nellcor Board is authorized to  issue Nellcor Preferred Stock from time
to time in one or more series, to  fix the number of shares of any such  series,
to  determine  or alter  the  rights, preferences,  privileges  and restrictions
granted to or imposed upon any wholly unissued series of Nellcor Preferred Stock
and, within the limits and restrictions stated in any resolution or  resolutions
of  the Nellcor  Board originally fixing  the number of  shares constituting any
series, to  increase  or  decrease the  number  of  shares of  any  such  series
subsequent to the issue of shares of that series.

    As  of July 19, 1995, no shares of Nellcor Preferred Stock were outstanding,
and 500,000 shares of Series A Preferred Stock (as defined below) were  reserved
for issuance upon exercise of Nellcor's Preferred Stock Purchase Rights. See "--
Preferred Stock Purchase Rights."

    On  June 11,  1991 the  Nellcor Board  designated 500,000  shares of Nellcor
Preferred Stock as "Series A Junior Participating Preferred Stock" (the  "Series
A  Preferred Stock").  The Series  A Preferred  Stock will  be nonredeemable and
junior to any other series of Nellcor Preferred Stock (unless otherwise provided
in the terms of such stock). Each share of Series A Preferred Stock will have  a
minimum  preferential quarterly dividend of 100  times the dividend declared per
share of

                                       85
<PAGE>
Nellcor Common  Stock. In  the event  of liquidation,  the holders  of Series  A
Preferred  Stock will be entitled to  a minimum preferential liquidation payment
of $100 per share but will be entitled to an aggregate payment of 100 times  the
payment made per Nellcor Common Stock. In the event of any merger, consolidation
or other transaction in which shares of Nellcor Common Stock are exchanged, each
share  of Series  A Preferred Stock  will be  entitled to receive  100 times the
amount received per share of Nellcor Common Stock. These rights are protected by
customary anti-dilution provisions. For a description of the rights pursuant  to
which  the  Series A  Preferred Stock  may  be issued,  see "--  Preferred Stock
Purchase Rights."

PREFERRED STOCK PURCHASE RIGHTS

    The Nellcor Board has authorized and  directed the issuance of one right  (a
"Nellcor  Preferred Stock Purchase Right") with respect to each share of Nellcor
Common Stock that becomes outstanding prior to the earliest of the  Distribution
Date,  the Redemption  Date and  the Final  Expiration Date  (as such  terms are
defined below). Each Nellcor Preferred Stock Purchase Right represents the right
to purchase one one-hundredth of a share of Series A Preferred Stock at a  price
of  $90.00, subject to  adjustment (the "Purchase Price").  For a description of
the terms of the Series A Preferred Stock, see "-- Nellcor Preferred Stock." The
Purchase Price and the  number of shares  of Series A  Preferred Stock or  other
securities  or property  issuable upon exercise  of the  Nellcor Preferred Stock
Purchase Rights are subject to adjustment from time to time to prevent dilution.

    The  Nellcor  Preferred  Stock  Purchase  Rights  presently  are  issued  in
connection with the Rights Agreement between Nellcor and The First National Bank
of  Boston, as Rights Agent, dated as  of September 1, 1992 (the "Nellcor Rights
Agreement"). The following summary of  certain aspects of the Nellcor  Preferred
Stock  Purchase Rights is qualified in its  entirety by reference to the Nellcor
Rights Agreement,  a copy  of which  is incorporated  herein by  reference.  See
"Incorporation  of  Documents  by  Reference." Nellcor  may  from  time  to time
supplement or amend  the Nellcor Rights  Agreement without the  approval of  any
holder  of  a  Nellcor Preferred  Stock  Purchase  Right in  order  to  make any
provisions with respect to the Rights which may it deem necessary or  desirable,
provided that after such time as any Person becomes an Acquiring Person (as such
terms  are defined below) the  Nellcor Rights Agreement shall  not be amended in
any manner which would adversely affect the interests of the holders of Rights.

    The Nellcor Preferred Stock  Purchase Rights are  not exercisable until  the
date  (the "Distribution Date") which is the  earlier of (i) the tenth day after
the date (the "Shares  Acquisition Date") of public  announcement by Nellcor  or
any  individual, firm, corporation or other entity (each a "Person") that such a
Person, together with all its affiliates and associates (an "Acquiring  Person")
has  acquired, or obtained the right to  acquire, beneficial ownership of 15% or
more of Nellcor Common  Stock then outstanding and  (ii) the tenth business  day
(or such later date as may be determined by action of the Nellcor Board prior to
such  time  as  any  person  becomes an  Acquiring  Person)  after  the  date of
commencement by  any Person  of, or  of  the first  public announcement  of  the
intention  of  any Person  to commence,  a  tender offer  or exchange  offer the
consummation of which would result in  any Person becoming an Acquiring  Person.
The  Nellcor Preferred Stock  Purchase Rights expire  at the earlier  of (i) the
close of business on June 26, 2001 (the "Final Expiration Date"), (ii) the  date
(the  "Redemption Date") of  redemption of the  Nellcor Preferred Stock Purchase
Rights by  Nellcor  as described  below  and (iii)  exchange  of the  rights  as
described  below.  Until  the  Distribution Date,  the  Nellcor  Preferred Stock
Purchase Rights will  be transferred  only in  connection with  the transfer  of
Nellcor Common Stock.

    In the event that an Acquiring Person becomes such, each holder of a Nellcor
Preferred  Stock  Purchase Right  (other than  Nellcor Preferred  Stock Purchase
Rights beneficially owned by  an Acquiring Person which  will have become  void)
shall,  for  a period  of 60  days after  the expiration  or termination  of the
redemption option as described below, have a right to receive, at a price  equal
to the Purchase Price multiplied by the number of one one-hundredths of Series A
Preferred  Stock  for which  a Nellcor  Preferred Stock  Purchase Right  is then
exercisable (and in lieu of the Series A Preferred

                                       86
<PAGE>
Stock), such number of  shares of Nellcor  Common Stock as  shall equal (i)  the
product  of the Purchase Price multiplied by the number of one one-hundredths of
Series A Preferred Stock for which a  Right is then exercisable (ii) divided  by
50%  of the  per share  market price  of Nellcor  Common Stock  on the  date the
Acquiring Person became such, or, in certain circumstances, cash, securities  or
any property of equal value.

    In  the  event  that,  following the  Shares  Acquisition  Date,  Nellcor is
involved in a consolidation or merger with any other Person, and Nellcor is  the
continuing  or surviving  corporation, or Nellcor  (or one  of its subsidiaries)
sells, mortgages or otherwise transfers, in one or more transactions, assets  or
earning  power  aggregating more  than 50%  of  the assets  or earning  power of
Nellcor and its  subsidiaries (taken  as a whole)  to any  other Person,  proper
provision  shall be made  so that (i)  each holder of  a Nellcor Preferred Stock
Purchase Right (other than Nellcor Preferred Stock Purchase Rights  beneficially
owned by an Acquiring Person which will thereafter be void) shall have the right
to  receive, upon the exercise  thereof, at a price  equal to the Purchase Price
multiplied by the number of one  one-hundredths of Series A Preferred Stock  for
which  a Nellcor Preferred Stock Purchase Right is then exercisable (and in lieu
of Series A Preferred  Stock), such number of  shares of freely tradable  common
stock of the other party to such transaction (the "Principal Party") as shall be
equal  to (a) the product of the Purchase  Price multiplied by the number of one
one-hundredths of Series A Preferred Stock  for which a Nellcor Preferred  Stock
Purchase  Right is then exercisable  (b) divided by 50%  of the per share market
price of the common stock  to be received on the  date of such transaction,  and
(ii)  the Principal Party shall  thereafter be liable for,  and shall assume, by
virtue of such transaction, all the  obligations and duties of Nellcor  pursuant
to the Nellcor Rights Agreement.

    At  any time after the Shares Acquisition  Date and prior to the acquisition
by an Acquiring Person of 50% or  more of the outstanding Nellcor Common  Stock,
the  Nellcor  Board may  exchange the  Nellcor  Preferred Stock  Purchase Rights
(other than  Nellcor Preferred  Stock Purchase  Rights owned  by such  Acquiring
Person which will become void), in whole or in part, at an exchange ratio of one
share  of Nellcor  Common Stock, or  one one-hundredths  of a share  of Series A
Preferred Stock  (or of  an share  of Equivalent  Preferred Stock),  per  Right,
subject to adjustment.

    At  any time prior  to the earliest  of (i) the  twentieth day following the
Shares Acquisition  Date  or  such date  more  than  20 days  after  the  Shares
Acquisition  Date to which  such option has  been extended by  the Nellcor Board
prior to the twentieth day following the Shares Acquisition Date, (ii) such time
on or after the Shares Acquisition Date as there shall have occurred a Change of
Control (as  defined in  the  Nellcor Rights  Agreement),  and (iii)  the  Final
Expiration  Date,  Nellcor  may  redeem  all but  not  less  than  all  the then
outstanding Nellcor Preferred  Stock Purchase  Rights at a  redemption price  of
$0.001  per  Right, appropriately  adjusted to  reflect  any stock  split, stock
dividend or similar transaction occurring after  the date of the Nellcor  Rights
Agreement  (the "Redemption Price"), and Nellcor may pay the Redemption Price in
Nellcor Common Stock, cash or any other form of consideration.

    The Nellcor  Preferred  Stock  Purchase Rights  have  certain  anti-takeover
effects.  The  Nellcor Preferred  Stock Purchase  Rights will  cause substantial
dilution to a Person that attempts  to acquire Nellcor without conditioning  the
offer  on  the  Nellcor Preferred  Stock  Purchase  Rights being  redeemed  or a
substantial number of such  Rights being acquired.  The Nellcor Preferred  Stock
Purchase  Rights  should  not  interfere  with  any  merger  or  other  business
combination approved by the Nellcor Board prior to twenty days after the  Shares
Acquisition  Date, as such Rights may be redeemed by Nellcor at $0.001 per Right
prior to such time, subject to adjustment.

                        COMPARISON OF STOCKHOLDER RIGHTS

GENERAL

    As a  result  of  the  Merger,  holders of  P-B  Common  Stock  will  become
stockholders  of Nellcor and the rights of all such former P-B stockholders will
thereafter be governed by the Nellcor Restated Certificate of Incorporation  and
By-Laws  and  the  DGCL. The  rights  of the  holders  of P-B  Common  Stock are
presently governed by the P-B Restated Certificate of Incorporation and  By-Laws
and the

                                       87
<PAGE>
DGCL.  The following summary, which does not  purport to be a complete statement
of the general differences between the rights of the stockholders of Nellcor and
P-B, sets  forth  certain  differences  between the  Nellcor  and  P-B  Restated
Certificates  of Incorporation  and By-Laws.  This summary  is qualified  in its
entirety by reference to the full text  of each of such documents and the  DGCL.
For  information  as  to how  such  documents  may be  obtained,  see "Available
Information."

CLASSIFIED BOARD OF DIRECTORS

    The DGCL provides  that a corporation's  board of directors  may be  divided
into  various  classes  with staggered  terms  of office.  The  Nellcor Restated
Certificate of Incorporation does not contain any classification provisions. The
P-B Restated Certificate of Incorporation, however, provides that the P-B  Board
is  divided  into three  classes  of directors,  as  nearly equal  in  number as
possible, and that one class of directors is elected each year for a  three-year
term.

    Classification  of directors has the effect  of making it more difficult for
stockholders to change the composition of  the board of directors. At least  two
annual  meetings of stockholders, instead of  one, will generally be required to
effect a change in the majority of the board of directors. Such a delay may help
ensure that the directors, if confronted by a holder attempting to force a proxy
contest,  a  tender   or  exchange  offer   or  other  extraordinary   corporate
transaction,  would have sufficient time  to review the proposal  as well as any
available alternatives to the proposal and to act in what they believe to be  in
the best interests of the stockholders. The classification provisions could also
have  the effect of discouraging a third  party from initiating a proxy contest,
making  a  tender  offer  or  otherwise  attempting  to  obtain  control  of   a
corporation,  even  though  such  a  transaction  could  be  beneficial  to  the
corporation and its  stockholders. The  classification of the  board might  also
increase the likelihood that incumbent directors will retain their positions.

STOCKHOLDERS RIGHTS PLAN

    Nellcor  has adopted a  stockholder rights plan that  is designed to protect
Nellcor stockholders from coercive or unfair takeover tactics. In general,  upon
the  occurrence of specified  triggering events, such as  the acquisition by any
person (other  than  Nellcor or  any  of  its subsidiaries)  of  the  beneficial
ownership  of securities representing  15% or more of  the Nellcor Common Stock,
Nellcor's stockholders  other than  Acquiring Persons  shall have  the right  to
acquire  one one-hundredth of a share of  Series A Preferred Stock at a purchase
price of $90.00, subject to adjustment. The Series A Preferred Stock will not be
redeemable and  will  have certain  dividend  and liquidation  preferences  over
Nellcor  Common Stock. The  holders of a Nellcor  Preferred Stock Purchase Right
(other than Nellcor  Preferred Stock  Purchase Rights beneficially  owned by  an
Acquiring  Person  which will  have become  void) have  the right  under certain
circumstances upon exercise of the Right and in lieu of Series A Preferred Stock
to receive that  amount of Nellcor  Common Stock (or  in certain  circumstances,
cash, property or other securities of Nellcor) having a value equal to two times
the  purchase  price.  The Nellcor  Rights  Agreement further  provides  that if
Nellcor is  acquired in  a merger  or other  business combination  which is  not
approved  by the Nellcor  Board, Nellcor's stockholders shall  have the right to
receive common stock of the acquiring company having a value equal to two  times
the  purchase price. Under certain circumstances,  Nellcor may redeem the Rights
at a redemption price of $0.001  per Nellcor Preferred Stock Purchase Right,  or
exchange the Nellcor Preferred Stock Purchase Rights at an exchange ratio of one
share  of Nellcor Common  Stock per Nellcor Preferred  Stock Purchase Right, and
the Nellcor Preferred Stock  Purchase Rights otherwise will  expire on June  26,
2001.  See "Description of Capital Stock  of Nellcor -- Preferred Stock Purchase
Rights." The  effect of  the Nellcor  Rights  Agreement may  be to  render  more
difficult a change in control of Nellcor.

    P-B  presently has a  stockholders rights plan (the  "P-B Rights Plan"), the
description and terms of which are set  forth in the Rights Agreement (the  "P-B
Rights  Agreement") between P-B and UMB Bank, N.A., as Rights Agent, dated as of
May 2, 1989, as amended. The P-B Rights Agreement generally contains  provisions
which  are similar  to those  of the Nellcor  Rights Agreement  described in the
previous paragraph, except  that (i) each  right (a "P-B  Common Stock  Purchase
Right")  under  the  P-B  Rights Agreement  initially  represents  the  right to
purchase one-half share of P-B Common Stock,

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(ii) the  threshold for  the acquisition  of P-B  Common Stock  to be  an  event
triggering  the exercisability of the  Rights is 20% of  P-B Common Stock, (iii)
the redemption price is $0.01 per right, (iv) there are no exchange  provisions,
and (v) the rights expire on May 1, 1999. The foregoing summary of certain terms
of  the P-B  Rights Plan is  qualified in its  entirety by reference  to the P-B
Rights Agreement,  a copy  of which  is incorporated  herein by  reference.  See
"Incorporation of Documents by Reference."

ELECTION AND NUMBER OF DIRECTORS; FILLING VACANCIES; REMOVAL

    The  Nellcor By-Laws provide that elections of directors shall be by written
ballot  unless  otherwise  provided  in  the  Nellcor  Restated  Certificate  of
Incorporation,  which provides that such elections need not be by written ballot
unless the  By-Laws  otherwise  provide. The  Nellcor  Restated  Certificate  of
Incorporation  and By-Laws provide for cumulative  voting rights in elections of
directors (see  "Description  of Capital  Stock  of Nellcor  --  Nellcor  Common
Stock").  The Nellcor  By-Laws also  disqualify from  nomination to  the Nellcor
Board any person 72 years  of age or older,  subject to certain exceptions.  The
P-B  Certificate of  Incorporation and By-Laws  do not  contain such provisions,
other than to provide that written ballots are not required unless the  Chairman
of  the  P-B Board  so directs  or it  is required  by law.  However, P-B  has a
retirement policy for directors comparable to Nellcor's.

    The Nellcor By-Laws  provide that the  number of directors  shall be six  or
such  other number as may be designated from  time to time by the members of the
Nellcor Board then in  office. The P-B By-Laws  contain a comparable  provision,
except  that the number of directors is to be no less than five and no more than
ten.

    The Nellcor  By-Laws provide  that any  vacancies (including  newly  created
directorships)  may be filled  by a majority of  the remaining directors, though
less than a quorum. The P-B By-Laws contain a comparable provision.

    Under  the  DGCL,   unless  otherwise   provided  in   the  certificate   of
incorporation, any director or the entire board of directors may be removed with
or  without cause. The Nellcor By-Laws  explicitly provide that directors may be
removed with or without  cause, provided that, if  less than the entire  Nellcor
Board  is to be removed, no directors may  be removed without cause if the votes
cast against his removal would be  sufficient to elect him if then  cumulatively
voted  at an election of  the entire Board of  Directors. The P-B Certificate of
Incorporation and By-Laws provide that directors of P-B may be removed only  for
cause.

    Both  the Nellcor and P-B By-Laws allow their respective Boards of Directors
to establish  committees. The  Nellcor By-Laws  require each  such committee  to
consist  of one  or more directors,  while the  P-B By-Laws require  two or more
directors. The Nellcor By-Laws provide that  such committees shall not have  the
power  to amend the Nellcor Restated  Certificate of Incorporation or By-Laws or
to adopt or  recommend to the  stockholders certain corporate  actions. The  P-B
By-Laws do not contain such a provision.

STOCKHOLDERS MEETINGS

    The  Nellcor By-Laws provide  that special meetings  of Nellcor stockholders
may be called by Nellcor's President  or Chief Executive Officer or the  Nellcor
Board  at any time,  and that Nellcor's  Secretary shall call  a special meeting
upon the request of any stockholder or stockholders holding in the aggregate 10%
of the voting power  of all stockholders. The  P-B By-Laws provide that  special
meetings of P-B stockholders may be called only by the Chairman of the P-B Board
and,  at the request  of the majority  of P-B's directors,  P-B's Secretary, and
disclaim the right of any other person to call a special meeting.

    The Nellcor By-Laws provide a procedure for nominating persons to be elected
to the Nellcor Board including, among other things, the requirement of not  less
than  30 nor more  than 60 days' notice  prior to the  scheduled meeting and the
provision of certain information about the nominee. The P-B By-Laws also provide
certain procedures  regarding  nominations of  persons  to the  P-B  Board,  and
further  provide procedures regarding stockholder proposals generally, including
in both cases, among  other things, the  requirement of not  less than 60  days'
notice prior to the scheduled meeting and the

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provision  of certain information about the proposal or the nominee, as the case
may be. Although the respective procedures for nominating persons to the  Boards
of Directors of Nellcor and P-B do not give the Board of Directors of Nellcor or
P-B,  as  the  case may  be,  any  power to  approve  or  disapprove stockholder
nominations for  the  election  of  directors,  they  may  have  the  effect  of
precluding  a contest for the election of directors if the proper procedures are
not followed, and of discouraging or  deterring a third party from conducting  a
solicitation  of proxies to elect its own  slate of directors, without regard to
whether consideration of  such nominees might  be harmful or  beneficial to  the
corporation or its stockholders.

    The  Nellcor By-Laws provide  that any notice  requirements for stockholders
meetings may be waived and will be  waived by any stockholder by his  attendance
thereat,  except when the stockholder attends  a meeting for the express purpose
of objecting,  at  the beginning  of  the meeting,  to  the transaction  of  any
business because the meeting is not lawfully called or convened. The P-B By-Laws
contain a similar provision.

    The  Nellcor By-Laws  provide that any  action by stockholders  may be taken
without a meeting,  without prior notice  and without  a vote, if  a consent  in
writing shall be signed by the holders of outstanding stock having not less than
the  minimum number of votes  that would be necessary  to authorize or take such
action at a meeting at  which all shares entitled  to vote thereon were  present
and voted. The P-B Restated Certificate of Incorporation denies the power of the
stockholders to consent in writing to the taking of any action without a meeting
and without a vote. The denial of stockholder action by written consent, coupled
with  the restrictions  described above  on the  calling of  special meetings of
stockholders, may have  the effect  of delaying consideration  of a  stockholder
proposal  until the next annual meeting  of stockholders. Such denial also would
prevent holders of a majority of the voting power of P-B stock from unilaterally
using the written consent procedures to take stockholder action.

STOCKHOLDERS VOTE FOR BUSINESS COMBINATIONS

    The Nellcor Restated  Certificate of Incorporation  contains a "fair  price"
provision, requiring that, in addition to any other vote required by the Nellcor
Restated Certificate of Incorporation or the DGCL, certain Business Combinations
with  an  Interested Stockholder  or any  affiliate thereof  (as such  terms are
defined below) will be  subject to the  affirmative vote of  the holders of  not
less than 66 2/3% of the outstanding stock of Nellcor entitled to generally vote
in the elections of directors (the "Voting Stock").

    For  the purpose of the  fair price provision, certain  terms are defined as
follows:

    "Business Combination" means (a) any merger or consolidation of Nellcor or a
subsidiary of Nellcor with an  Interested Stockholder or any affiliate  thereof,
(b)  any sale, lease, exchange, mortgage,  pledge, transfer or other disposition
other than  in  the  ordinary  course  of business  to  or  with  an  Interested
Stockholder or any affiliate thereof of any assets of Nellcor or a subsidiary of
Nellcor  having an aggregate Fair Market Value (as hereinafter defined) equal to
or greater  than 10%  of  Nellcor's assets,  (c) the  adoption  of any  plan  or
proposal  for the liquidation or dissolution of Nellcor proposed by or on behalf
of  an   Interested  Stockholder   or  any   affiliate  thereof,   or  (d)   any
reclassification   of  securities   (including  any  reverse   stock  split)  or
recapitalization of Nellcor, or any merger or consolidation of Nellcor with  any
of  its subsidiaries or any other transaction which has the effect of increasing
the proportionate share  of the  outstanding shares of  any class  of equity  or
convertible securities of Nellcor or any subsidiary of Nellcor which is directly
or indirectly owned by any Interested Stockholders or any affiliate thereof.

    "Interested  Stockholder" means  any individual, firm,  corporation or other
entity that is (a) the beneficial owner of more than 20% of the voting power  of
the  outstanding Voting Stock, (b)  an affiliate of Nellcor  and that was at any
time within the two-year  period immediately prior to  the date in question  the
beneficial  owner of  20% or more  of the  voting power of  the then outstanding
Voting Stock, or (c) an assignee of or has otherwise succeeded to any shares  of
Voting Stock that were at any

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time  within  the two-year  period  immediately prior  to  the date  in question
beneficially  owned  by  any  Interested  Stockholder  if  such  assignment   or
succession  shall have  occurred in  the course  of a  transaction or  series of
transactions  not  involving  a  public  offering  within  the  meaning  of  the
Securities Act.

    "Fair  Market Value"  means (a)  in the  case of  stock, the  average of the
closing sale prices during the 10-day  period immediately preceding the date  in
question,  or (b)  in the case  of property other  than cash or  stock, the fair
market value of  such property  on the  date in  question as  determined by  the
Nellcor Board in good faith.

    "Disinterested  Directors"  means any  member of  the  Nellcor Board  who is
unaffiliated with the  Interested Stockholder and  was a member  of the  Nellcor
Board  prior to  the time that  the Interested Stockholder  became an Interested
Stockholder and any successor  of a Disinterested  Director who is  unaffiliated
with  the Interested Stockholder  and is recommended  to succeed a Disinterested
Director by the majority of Disinterested Directors then on the Nellcor Board.

    The 66  2/3% voting  requirement  will not  be  applicable to  any  Business
Combination  if either (1) the Business  Combination is approved by the majority
of the  Disinterested Directors  or  (2) all  of  the following  conditions  are
satisfied:

        (a)  The aggregate amount  of cash and  the Fair Market  Value as of the
    date of consummation of the Business Combination of consideration other than
    cash (the "Consideration") to  be received per share  by holders of  Nellcor
    Common  Stock in such  Business Combination shall  be at least  equal to the
    higher of:  (i) (if  applicable) the  highest per  share price  paid by  the
    Interested Stockholder for any shares of Nellcor Common Stock acquired by it
    within   the  two-year  period   immediately  prior  to   the  first  public
    announcement of the proposal of the Business Combination (the  "Announcement
    Date")  or in the transaction in  which it became an Interested Stockholder,
    whichever is higher;  and (ii) the  Fair Market Value  per share of  Nellcor
    Common  Stock on  the Announcement Date  or on the  date (the "Determination
    Date") on which the Interested Stockholder became an Interested Stockholder,
    whichever is higher.

        (b) The Consideration to be received  per share by holders of shares  of
    any  other class of outstanding Voting Stock  shall be at least equal to the
    highest of: (i)  (if applicable)  the highest per  share price  paid by  the
    Interested Stockholder for any shares of such class of Voting Stock acquired
    by  it within the two-year period immediately prior to the Announcement Date
    or in  the  transaction  in  which  it  became  an  Interested  Stockholder,
    whichever  is higher, (ii)  (if applicable) the  highest preferential amount
    per share to which the holders of  shares of such class of Voting Stock  are
    entitled   in  the  event  of  any  voluntary  or  involuntary  liquidation,
    dissolution or winding up  of Nellcor, and (iii)  the Fair Market Value  per
    share  of such  class of  Voting Stock  on the  Announcement Date  or on the
    Determination Date, whichever is higher.

        (c) The consideration to be received by holders of any particular  class
    of  outstanding Voting  Stock shall be  in cash or  in the same  form as the
    Interested Stockholder previously paid  for shares of  such class of  Voting
    Stock.

        (d)  A proxy or  information statement describing  the proposed Business
    Combination and complying with  the Exchange Act shall  be mailed to  public
    stockholders  of Nellcor at least 30 days  prior to the consummation of such
    Business Combination.

    The fair price provision is intended to ensure that all stockholders receive
equal treatment  in the  event of  a tender  or exchange  offer and  to  protect
stockholders  against coercive or two-tiered  takeover bids. Notwithstanding the
foregoing, the provision  could also  have the  effect of  discouraging a  third
party  from making a tender  or exchange offer for  Nellcor, even though such an
offer might be beneficial to Nellcor and its stockholders.

    The P-B  Restated  Certificate  of  Incorporation  also  requires  that  any
proposal  for the merger or consolidation of P-B,  or the sale or lease or other
transfer   of    substantially   all    of   P-B's    assets,   with    or    to

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a  Major Stockholder  (as defined  below) or  any other  person or  other entity
controlling, controlled by or under common control with such Major  Stockholder,
in  addition to receiving such other  vote as may be required  by law or the P-B
Restated Certificate of  Incorporation, be  approved at  a stockholders  meeting
held  to act on such proposal by the favorable  vote of not less than 66 2/3% of
the outstanding voting stock entitled to cast thereon. "Major Stockholder" shall
mean any person or other entity,  or any combination, association, syndicate  or
other  organization thereof acting  in concert, directly  or indirectly, for the
purpose of carrying out or obtaining  the approval, or otherwise in respect  of,
such  proposal and which owns of record or beneficially, directly or indirectly,
or is otherwise entitled to vote, whether by agreement or otherwise, that number
of shares of P-B's voting stock, regardless of class or series, constituting  5%
or more of the total votes which may be cast with respect to any such proposal.

    Such  provision of  the P-B Restated  Certificate of  Incorporation shall be
inapplicable if the  proposal in  question first  shall have  been approved  and
recommended to the stockholders by the favorable vote of at least 66 2/3% of the
whole P-B Board.

COMMON STOCK

    The terms of the Nellcor Common Stock are substantially the same as those of
the P-B Common Stock.

PREFERRED STOCK

    Pursuant  to the Nellcor Restated  Certificate of Incorporation, the Nellcor
Board is authorized, subject  to the limitations prescribed  by law, to  provide
for the issuance of shares of Nellcor Preferred Stock in one or more series. See
"Description  of  Capital  Stock of  Nellcor  -- Nellcor  Preferred  Stock." The
Nellcor Board has issued certain  rights to purchase, under certain  conditions,
shares of Series A Preferred Stock. See "Description of Capital Stock of Nellcor
- --   Preferred  Stock  Purchase   Rights."  The  P-B   Restated  Certificate  of
Incorporation contains no similar provisions relating to Preferred Stock.

    Nellcor believes that the ability of the Nellcor Board to issue one or  more
series   of  Nellcor  Preferred  Stock  provides  Nellcor  with  flexibility  in
structuring possible future  financings and acquisitions,  and in meeting  other
corporate  needs that  might arise. The  authorized shares  of Nellcor Preferred
Stock, as well  as shares of  Nellcor Common Stock,  are available for  issuance
without  further action by Nellcor stockholders,  unless such action is required
by applicable law  or the  rules of any  stock exchange  or automated  quotation
system  on which  Nellcor securities may  be listed or  traded. Nasdaq currently
requires stockholder approval in connection with, among other matters, the  sale
or  issuance of  common stock (or  securities or securities  convertible into or
exercisable for common stock) equal to 20% or more of the common stock or 20% or
more of  the voting  power outstanding  before the  issuance for  less than  the
greater of book value or market value of the stock.

    Although the Nellcor Board has no intention at the present time of doing so,
it  could issue a series of Nellcor Preferred Stock that could, depending on the
terms of such series, impede the completion  of a merger, tender offer of  other
takeover  attempt. The Nellcor  Board will make any  determination to issue such
shares based  on its  judgment  as to  the best  interests  of Nellcor  and  its
stockholders.  The Nellcor  Board, in so  acting, could  issue Nellcor Preferred
Stock having  terms that  discourage  an acquisition  attempt through  which  an
acquiror may be able to change the composition of the Nellcor Board, including a
tender  offer  or  other transaction  that  some,  or a  majority,  of Nellcor's
stockholders  might  believe  to  be  in  their  best  interests  or  in   which
stockholders  might  receive a  premium for  their stock  over the  then current
market price of such stock.

BUSINESS COMBINATIONS

    Section 203  of  the  DGCL  provides that,  subject  to  certain  exceptions
specified  therein, a corporation  shall not engage  in any business combination
with any "interested  stockholder" for  a three-year period  following the  date
that  such stockholder  becomes an interested  stockholder, unless  (i) prior to
such date,  the  board of  directors  of  the corporation  approved  either  the
business combination or the

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transaction   which  resulted   in  the   stockholder  becoming   an  interested
stockholder, (ii) upon  consummation of  the transaction which  resulted in  the
stockholder becoming an interested stockholder, the interested stockholder owned
at  least 85% of the voting stock of the corporation outstanding at the time the
transaction commenced (excluding shares held by directors who are also  officers
and  employees stock purchase  plans in which employee  participants do not have
the right to determine confidentially whether plan shares will be tendered in  a
tender  or exchange offer) or (iii) on  or subsequent to such date, the business
combination is approved by the board of directors of the corporation and by  the
affirmative vote at an annual or special meeting, and not by written consent, of
at  least 66  2/3% of  the outstanding voting  stock which  is not  owned by the
interested stockholder.  Except as  specified in  Section 203  of the  DGCL,  an
interested stockholder is defined to include (a) any person that is the owner of
15%  or  more  of the  outstanding  voting stock  of  the corporation  or  is an
affiliate or associate of the  corporation and was the owner  of 15% or more  of
the  outstanding voting stock of the corporation, at any time within three years
immediately prior to the relevant date and (b) the affiliates and associates  of
any such person.

    Under  certain  circumstances, Section  203  of the  DGCL  may make  it more
difficult for  a person  who  would be  an  "interested stockholder"  to  effect
various  business  combinations  with  a corporation  for  a  three-year period,
although the  corporation's certificate  of  incorporation or  stockholders  may
elect  to exclude  a corporation from  the restrictions  imposed thereunder. The
Nellcor Restated Certificate of Incorporation does not exclude Nellcor from  the
restrictions  imposed  under  section  203  of  the  DGCL.  Similarly,  the  P-B
Certificate of Incorporation does not exclude P-B from the restrictions  imposed
under  section 203. It is anticipated that  the provisions of Section 203 of the
DGCL may encourage  companies interested  in acquiring Nellcor  to negotiate  in
advance with the Nellcor Board, since the stockholder approval requirement would
be  avoided if  a majority of  the directors  then in office  approve either the
business combination  or  the  transaction  which  results  in  the  stockholder
becoming an interested stockholder.

LIMITATION OF LIABILITY OF DIRECTORS

    The  DGCL permits a corporation to include a provision in its certificate of
incorporation eliminating or limiting  the personal liability  of a director  to
the  corporation or its stockholders for damages  for a breach of the director's
fiduciary duty, subject  to certain  limitations. Each  of the  Nellcor and  P-B
Restated Certificates of Incorporation includes such a provision, to the maximum
extent  permitted by, in the case of  Nellcor, Section 102(b)(7) of the DGCL or,
in the case of P-B, the DGCL.

    Section 102(b)(7) of the DGCL provides that a corporation may include in its
certificate of incorporation  a provision eliminating  or limiting the  personal
liability  of a  director to  the corporation  or its  stockholders for monetary
damages for breach of fiduciary duty as a director, except for liability (i) for
any breach  of  the  director's  duty  of loyalty  to  the  corporation  or  its
stockholders,  (ii) for  acts or  omissions not in  good faith  or which involve
intentional misconduct or a knowing violation of law, (iii) under Section 174 of
the DGCL,  which concerns  unlawful payments  of dividends,  stock purchases  or
redemptions  or  (iv) for  any transaction  from which  the director  derived an
improper personal benefit.

INDEMNIFICATION OF DIRECTORS AND OFFICERS

    The DGCL permits a corporation  to indemnify officers, directors,  employees
and  agents for  actions taken  in good  faith and  in a  manner they reasonably
believe to be in, or not opposed  to, the best interest of the corporation,  and
with  respect to  any criminal  action, which  they had  no reasonable  cause to
believe was unlawful. The DGCL provides that a corporation may advance  expenses
of  defense (upon receipt of a  written undertaking to reimburse the corporation
if indemnification is not appropriate) and must reimburse a successful defendant
for expenses,  and permits  a  corporation to  purchase and  maintain  liability
insurance for its directors and officers. The DGCL provides that indemnification
may  not be made for  any claim, issue or  matter as to which  a person has been
adjudged to be liable to the corporation, unless and only to the extent a  court
determines  that the person  is entitled to  indemnity for such  expenses as the
court deems proper.

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    The  Nellcor By-Laws provide  that Nellcor shall  indemnify its directors to
the fullest extent permitted by the DGCL, as the same exists or may hereafter be
amended (but,  in  the case  of  alleged  occurrences of  actions  or  omissions
preceding  any such  amendment, only to  the extent that  such amendment permits
Nellcor to provide broader indemnification rights then permitted prior  thereto)
and  that Nellcor shall have the power  to indemnify its officers, employees and
other agents as set forth in the DGCL.

    The P-B By-Laws provide that  each person who is  involved in any actual  or
threatened  action, suit or proceeding,  whether civil, criminal, administrative
or investigative, by reason of the fact that  he or she is or was a director  or
officer  of P-B,  or is  or was  serving at  the request  of P-B  as a director,
officer, employee or  agent of another  corporation or of  a partnership,  joint
venture,  trust  or  other  enterprise, including  service  with  respect  to an
employee benefit plan, will be indemnified  by P-B to the full extent  permitted
by the DGCL, as the same exists or may hereafter be amended (but, in the case of
any  such  amendment, only  to the  extent  that such  amendment permits  P-B to
provide broader indemnification rights then permitted prior thereto) against all
expenses, liability and  loss reasonably incurred  in connection therewith.  The
P-B  By-Laws also provide  that P-B may,  to the extent  authorized from time to
time by the P-B Board, grant rights to indemnification to any employee or  agent
of  P-B to the fullest extent of the  provisions of the P-B By-Laws with respect
to the indemnification of directors and officers.

    The indemnification and advancement rights conferred by the Nellcor  By-Laws
are  not exclusive of  any other right to  which persons seeking indemnification
may be entitled under any statute, provision of the Nellcor Restated Certificate
of  Incorporation  or  By-Laws,  agreement,  or  vote  of  the  stockholders  or
disinterested directors. The P-B By-Laws contain a similar provision.

    The  Nellcor By-Laws specifically authorize  Nellcor to enter into contracts
with directors,  officers, employees  or agents  respecting indemnification  and
advances, to the fullest extent permitted by the DGCL.

    The  Nellcor  By-Laws  authorize  Nellcor, upon  approval  of  its  Board of
Directors, to purchase insurance on behalf  of any person required or  permitted
to  be indemnified pursuant  to such By-Laws.  The P-B By-Laws  authorize P-B to
maintain insurance  to protect  itself and  any director,  officer, employee  or
agent  of P-B against any  expense, liability or loss,  whether or not P-B would
have the power  under the DGCL  to indemnify such  person against such  expense,
liability  or loss. Additionally,  the Merger Agreement  requires Nellcor, for a
period of six years after the Effective Time, to maintain with respect to claims
arising from facts or events which occurred before the Effective Time, officers'
and directors'  liability insurance  for certain  persons currently  covered  by
P-B's  existing officers'  and directors'  liability insurance.  See "The Merger
Agreement -- Director and Officer Indemnification."

OTHER PROVISIONS

    The Nellcor Restated Certificate of Incorporation provides that the  Nellcor
Board  shall have full control  over the affairs of  Nellcor, and authorizes the
Nellcor Board, among  other things,  to transfer all  or any  part of  Nellcor's
assets  by way of mortgage, or in trust  or in pledge, to secure indebtedness of
Nellcor, and to sell, lease or exchange any part less than all or  substantially
all   of  the  property  and  assets  of  Nellcor,  in  each  case  without  any
authorization, affirmative  vote, written  consent or  other action  of  Nellcor
stockholders.   The  P-B  Restated  Certificate  of  Incorporation  contains  no
comparable provisions, although the  P-B By-Laws provide  that the business  and
affairs  of P-B shall be managed by the  P-B Board, except as required by law or
the P-B Restated Certificate of Incorporation or By-Laws.

    The Nellcor Restated Certificate of Incorporation provides that, whenever  a
compromise or arrangement is proposed between Nellcor and any class of or all of
its  creditors  or stockholders,  certain  courts may  order  a meeting  of such
creditors or stockholders and, if a majority representing three-fourths in value
of such creditors and/or of such stockholders agree to, and the court sanctions,

                                       94
<PAGE>
such compromise or  arrangement, then  such compromise or  arrangement shall  be
binding  on all such creditors or stockholders  and on Nellcor. The P-B Restated
Certificate of Incorporation does not contain a comparable provision.

AMENDMENT OF THE CERTIFICATE OF INCORPORATION AND BY-LAWS

    The Nellcor Restated Certificate of Incorporation provides that the  Nellcor
Board  reserves the right to amend, alter, change or repeal any provision of the
Nellcor Restated Certificate of Incorporation. The Nellcor Restated  Certificate
of  Incorporation  also provides  that the  affirmative vote  of the  holders of
66 2/3%  or more  of  the outstanding  voting stock  is  required to  amend  the
provisions described above under "Stockholders Vote for Business Combinations."

    The   Nellcor  Board,  pursuant  to  the  Nellcor  Restated  Certificate  of
Incorporation, may amend or repeal the Nellcor By-Laws without any action on the
part of the stockholders, provided that the stockholders may amend or repeal any
By-Laws made by the directors.

    The P-B Restated Certificate of Incorporation provides that P-B reserves the
right at any time and from time to time to amend or repeal any provision of  the
P-B  Restated Certificate of Incorporation, in the manner prescribed by law. The
P-B Restated Certificate of Incorporation also provides that the favorable  vote
of  the majority of the whole P-B Board  and the affirmative vote of the holders
of at  least 66  2/3% of  the  issued and  outstanding voting  stock of  P-B  is
required  to  amend  certain  provisions  of  such  Certificate,  including  the
provisions described above under "Stockholders Vote for Business  Combinations,"
certain  provisions with respect to the P-B Board and the denial of the power of
stockholders  to  take   action  by  written   consent  described  above   under
"Stockholders Meetings."

    The  P-B Restated Certificate  of Incorporation provides  that the P-B Board
may amend or repeal P-B's By-Laws. The P-B Restated Certificate of Incorporation
also provides that the P-B stockholders may amend or repeal the P-B By-Laws, but
only upon the favorable vote of not less  than 66 2/3% of all votes entitled  to
be cast, which provision may not be amended or repealed unless authorized by the
favorable  vote of a majority  of the whole P-B Board  and the favorable vote of
not less than 66 2/3% of the votes entitled to be cast thereon by the holders of
outstanding stock.

                                       95
<PAGE>
                        PROPOSED AMENDMENT TO NELLCOR'S
                     RESTATED CERTIFICATE OF INCORPORATION

    Pursuant to  the  Merger  Agreement,  Nellcor  agreed  to  take  all  action
necessary  to  submit to  its stockholders  an  amendment to  Nellcor's Restated
Certificate of  Incorporation  to change  Nellcor's  corporate name  to  Nellcor
Puritan  Bennett Incorporated, effective  as of the  Effective Time. The Nellcor
Charter Amendment  Proposal  would accomplish  that  name change.  The  form  of
proposed  amendment  to  Nellcor's  Restated  Certificate  of  Incorporation  is
attached as Annex F to this Proxy Statement/Prospectus. Approval of the  Nellcor
Charter Amendment Proposal is not a condition to the consummation of the Merger.

    THE  NELLCOR BOARD  HAS UNANIMOUSLY  APPROVED THE  NELLCOR CHARTER AMENDMENT
PROPOSAL AND UNANIMOUSLY  RECOMMENDS THAT  HOLDERS OF SHARES  OF NELLCOR  COMMON
STOCK VOTE "FOR" APPROVAL OF SUCH PROPOSAL.

                                 OTHER MATTERS

    It is not expected that any matters other than those described in this Proxy
Statement/Prospectus  will be brought before the  Nellcor Special Meeting or the
P-B Special Meeting.  If any  other matters are  presented, however,  it is  the
intention  of the persons named  in the Nellcor proxy and  the P-B proxy to vote
such proxies in accordance with their respective discretion.

                                 LEGAL MATTERS

    Certain legal matters with respect to the validity of the securities offered
hereby and the federal income tax consequences of the Merger will be passed upon
for Nellcor by Morrison  & Foerster. Certain legal  matters with respect to  the
federal  income tax consequences  of the Merger  will be passed  upon for P-B by
Blackwell Sanders Matheny Weary & Lombardi L.C.

                                    EXPERTS

    The  consolidated   financial   statements  incorporated   in   this   Proxy
Statement/Prospectus  by reference to  Nellcor's Annual Report  on Form 10-K for
the year ended July 3, 1994 have been so incorporated in reliance on the  report
of Price Waterhouse LLP, independent accountants, given on the authority of said
firm as experts in auditing and accounting.

    The  consolidated financial statements  of P-B incorporated  by reference in
P-B's  Annual  Report  (Form  10-K)  for  the  year  ended  January  31,   1995,
incorporated by reference in this Proxy Statement/ Prospectus, have been audited
by Ernst & Young LLP, independent auditors, as set forth in their report thereon
included  therein  and  incorporated  herein  by  reference.  Such  consolidated
financial statements are incorporated herein by reference in reliance upon  such
report  given  upon the  authority of  such  firm as  experts in  accounting and
auditing.

                             STOCKHOLDER PROPOSALS

    The deadline for proposals of stockholders  of Nellcor to be considered  for
inclusion  in the proxy statement of the  1995 Annual Meeting of Stockholders of
Nellcor, which is expected to be held in October 1995, has passed.

    For proposals of stockholders of P-B  to be considered for inclusion in  the
proxy statement of the 1996 Annual Meeting of Stockholders of P-B (if the Merger
is  not consummated), such proposals must be received by the Corporate Secretary
of P-B no later than January 20, 1996.

                                       96
<PAGE>
                   ANNEXES TO THE PROXY STATEMENT/PROSPECTUS

<TABLE>
<S>          <C>
ANNEX A      MERGER AGREEMENT
ANNEX B      AMENDMENT NO. 1 TO MERGER AGREEMENT
ANNEX C      OPINION OF ROBERTSON, STEPHENS & COMPANY, L.P.
ANNEX D      OPINION OF GOLDMAN, SACHS & CO.
ANNEX E      OPINION OF SMITH BARNEY INC.
ANNEX F      FORM OF AMENDMENT TO NELLCOR'S RESTATED CERTIFICATE OF INCORPORATION
</TABLE>

                                       97
<PAGE>
                                                                         ANNEX A

                          AGREEMENT AND PLAN OF MERGER
                            DATED AS OF MAY 21, 1995
                                  BY AND AMONG
                             NELLCOR INCORPORATED,
                            PUMA MERGER CORPORATION
                                      AND
                          PURITAN-BENNETT CORPORATION
<PAGE>
                               TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                                                              PAGE
                                                                                                            ---------
<S>                                                                                                         <C>
Agreement and Plan of Merger..............................................................................        A-1
Article I: The Merger.....................................................................................        A-1
  1.1 The Merger..........................................................................................        A-1
  1.2 Effective Time of the Merger........................................................................        A-1
Article II: The Surviving Corporation.....................................................................        A-1
  2.1 Certificate of Incorporation........................................................................        A-1
  2.2 By-Laws.............................................................................................        A-1
  2.3 Directors and Officers of Surviving Corporation.....................................................        A-1
Article III: Conversion of Shares.........................................................................        A-2
  3.1 Exchange Ratio......................................................................................        A-2
  3.2 Exchange of Shares..................................................................................        A-2
  3.3 Dividends; Transfer Taxes...........................................................................        A-3
  3.4 No Fractional Shares................................................................................        A-3
  3.5 Closing of P-B Transfer Books.......................................................................        A-4
  3.6 Closing.............................................................................................        A-4
  3.7 Supplementary Action................................................................................        A-4
Article IV: Representations and Warranties of Nellcor and Sub.............................................        A-4
  4.1 Organization........................................................................................        A-4
  4.2 Capitalization......................................................................................        A-5
  4.3 Authority Relative to this Agreement................................................................        A-6
  4.4 Consents and Approvals; No Violations...............................................................        A-6
  4.5 Reports and Financial Statements....................................................................        A-6
  4.6 Absence of Certain Changes or Events................................................................        A-7
  4.7 Information in Registration Statement and Proxy Statement...........................................        A-7
  4.8 Litigation..........................................................................................        A-7
  4.9 Contracts...........................................................................................        A-7
  4.10 Employee Benefit Plans.............................................................................        A-8
  4.11 Tax Matters........................................................................................       A-10
  4.12 Compliance with Applicable Law.....................................................................       A-12
  4.13 Subsidiaries.......................................................................................       A-12
  4.14 Section 203 of the DGCL Not Applicable.............................................................       A-12
  4.15 Labor and Employment Matters.......................................................................       A-12
  4.16 Ownership of Shares of P-B Common Stock............................................................       A-12
  4.17 Insurance..........................................................................................       A-13
  4.18 Contracts with Physicians, Hospitals, HMOs and Third Party Providers...............................       A-13
  4.19 Environmental Protection...........................................................................       A-13
  4.20 Intellectual Property Rights.......................................................................       A-14
  4.21 FDA and Related Matters............................................................................       A-15
  4.22 Real Property......................................................................................       A-17
  4.23 Rights Agreement...................................................................................       A-18
  4.24 Share Ownership....................................................................................       A-18
  4.25 Opinion of Financial Advisor.......................................................................       A-18
Article V: Representations and Warranties of P-B..........................................................       A-18
  5.1 Organization........................................................................................       A-18
  5.2 Capitalization......................................................................................       A-18
  5.3 Authority Relative to this Agreement................................................................       A-19
  5.4 Consents and Approvals; No Violations...............................................................       A-19
  5.5 Reports and Financial Statements....................................................................       A-20
</TABLE>

                                       i
<PAGE>
<TABLE>
<CAPTION>
                                                                                                              PAGE
                                                                                                            ---------
  5.6 Absence of Certain Changes or Events................................................................       A-20
<S>                                                                                                         <C>
  5.7 Information in Registration Statement and Proxy Statement...........................................       A-20
  5.8 Litigation..........................................................................................       A-20
  5.9 Contracts...........................................................................................       A-21
  5.10 Employee Benefit Plans.............................................................................       A-21
  5.11 Tax Matters........................................................................................       A-23
  5.12 Compliance with Applicable Law.....................................................................       A-25
  5.13 Subsidiaries.......................................................................................       A-25
  5.14 Section 203 of the DGCL Not Applicable.............................................................       A-25
  5.15 Labor and Employment Matters.......................................................................       A-25
  5.16 Ownership of Shares of Nellcor Common Stock........................................................       A-26
  5.17 Insurance..........................................................................................       A-26
  5.18 Contracts with Physicians, Hospitals, HMOs and Third Party Providers...............................       A-26
  5.19 Environmental Protection...........................................................................       A-26
  5.20 Intellectual Property Rights.......................................................................       A-27
  5.21 FDA and Related Matters............................................................................       A-28
  5.22 Real Property......................................................................................       A-29
  5.23 Rights Agreement...................................................................................       A-30
  5.24 Share Ownership....................................................................................       A-30
  5.25 Opinion of Financial Advisors......................................................................       A-30
Article VI: Conduct of Business Pending the Merger........................................................       A-30
  6.1 Conduct of Business by P-B and Nellcor Pending the Merger...........................................       A-30
  6.2 Conduct of Business of Sub..........................................................................       A-32
  6.3 Compensation Plans..................................................................................       A-32
  6.4 Current Information.................................................................................       A-32
  6.5 Letters of P-B's and Nellcor's Accountants..........................................................       A-32
  6.6 Legal Conditions to Merger..........................................................................       A-32
  6.7 Affiliates..........................................................................................       A-33
  6.8 Advise of Changes; Government Filings...............................................................       A-33
  6.9 Accounting Methods..................................................................................       A-33
Article VII: Additional Agreements........................................................................       A-33
  7.1 Access and Information..............................................................................       A-33
  7.2 No Solicitation of Transactions.....................................................................       A-34
  7.3 Registration Statement..............................................................................       A-34
  7.4 Proxy Statements; Stockholder Approvals.............................................................       A-34
  7.5 Nasdaq National Market..............................................................................       A-35
  7.6 Antitrust Law.......................................................................................       A-35
  7.7 Certain Employee Benefit Plans Matters..............................................................       A-35
  7.8 Stock Options and Warrants..........................................................................       A-36
  7.9 Director and Officer Indemnification, Etc...........................................................       A-37
  7.10 Public Announcements...............................................................................       A-37
  7.11 Expenses...........................................................................................       A-37
  7.12 Additional Agreements..............................................................................       A-38
  7.13 P-B Accruals and Reserves..........................................................................       A-38
  7.14 Certain Governance Matters.........................................................................       A-38
Article VIII: Conditions to Consummation of the Merger....................................................       A-39
  8.1 Conditions to Each Party's Obligation to Effect the Merger..........................................       A-39
  8.2 Conditions to Obligation of P-B to Effect the Merger................................................       A-40
  8.3 Conditions to Obligations of Nellcor and Sub to Effect the Merger...................................       A-41
</TABLE>

                                       ii
<PAGE>
<TABLE>
<CAPTION>
                                                                                                              PAGE
                                                                                                            ---------
Article IX: Termination, Amendment and Waiver.............................................................       A-42
<S>                                                                                                         <C>
  9.1 Termination.........................................................................................       A-42
  9.2 Effect of Termination...............................................................................       A-43
  9.3 Cancellation Fees; Expenses.........................................................................       A-43
  9.4 Amendment...........................................................................................       A-44
  9.5 Extension; Waiver...................................................................................       A-44
Article X: General Provisions.............................................................................       A-44
  10.1 Survival of Representations,Warranties and Agreements..............................................       A-44
  10.2 Brokers............................................................................................       A-45
  10.3 Notices............................................................................................       A-45
  10.4 Descriptive Headings...............................................................................       A-46
  10.5 Entire Agreement; Assignment.......................................................................       A-46
  10.6 Governing Law......................................................................................       A-46
  10.7 Parties in Interest................................................................................       A-46
  10.8 Counterparts.......................................................................................       A-46
  10.9 Validity...........................................................................................       A-46
  10.10 Jurisdiction and Venue............................................................................       A-46
  10.11 Investigation.....................................................................................       A-46
  10.12 Consents..........................................................................................       A-46
</TABLE>

                                      iii
<PAGE>
                          AGREEMENT AND PLAN OF MERGER

    AGREEMENT  AND PLAN OF MERGER, dated as of May 21, 1995 by and among Nellcor
Incorporated, a  Delaware corporation  ("Nellcor"), Puma  Merger Corporation,  a
Delaware  corporation  and a  wholly-owned  subsidiary of  Nellcor  ("Sub"), and
Puritan-Bennett Corporation, a Delaware corporation ("P-B").

    WHEREAS, the Boards  of Directors of  Nellcor and P-B  each have  determined
that  a strategic business  combination between Nellcor  and P-B is  in the best
interests of  their  respective  companies  and  stockholders  and  presents  an
opportunity  for their respective  companies to achieve  long-term strategic and
financial benefits, and accordingly  have agreed to  effect the merger  provided
for herein upon the terms and subject to the conditions set forth herein; and

    WHEREAS,  for federal  income tax purposes,  it is intended  that the merger
contemplated herein  shall qualify  as a  reorganization within  the meaning  of
Section  368 of the Internal Revenue Code  of 1986, as amended (the "Code"), and
for financial  accounting  purposes shall  be  accounted  for as  a  pooling  of
interests.

    NOW,  THEREFORE,  in  consideration  of  the  foregoing  and  the respective
representations, warranties,  covenants and  agreements  set forth  herein,  the
parties hereto agree as follows:

                                   ARTICLE I
                                   THE MERGER

    1.1   THE MERGER.  Subject to the terms and conditions of this Agreement, at
the Effective Time (as defined in Section 1.2 hereof), Sub shall be merged  with
and   into  P-B,  P-B  shall  be   the  surviving  corporation  (the  "Surviving
Corporation") and  the separate  existence  of Sub  shall thereupon  cease  (the
"Merger").  The Merger shall  have the effects  set forth in  Section 259 of the
General Corporation Law of  the State of Delaware  (the "DGCL"). From and  after
the Effective Time, the Surviving Corporation shall be a wholly-owned subsidiary
of Nellcor.

    1.2  EFFECTIVE TIME OF THE MERGER.  The Merger shall become effective when a
properly  executed Certificate  of Merger  is duly  filed with  the Secretary of
State of  the  State  of  Delaware,  which filing  shall  be  made  as  soon  as
practicable after the closing of the transactions contemplated by this Agreement
in  accordance  with  Section 3.6  hereof  upon  satisfaction or  waiver  of the
conditions set forth  in Article  VIII. When used  in this  Agreement, the  term
"Effective  Time" shall  mean the  date and  time at  which such  Certificate of
Merger is so filed.

                                   ARTICLE II
                           THE SURVIVING CORPORATION

    2.1  CERTIFICATE OF INCORPORATION.  The Certificate of Incorporation of  P-B
shall  be the Certificate of Incorporation  of the Surviving Corporation, except
that such Certificate of Incorporation shall be amended as of the Effective Time
as set forth in EXHIBIT 2.1 hereto.

    2.2  BY-LAWS.  The By-Laws of Sub  as in effect at the Effective Time  shall
be the By-Laws of the Surviving Corporation.

    2.3  DIRECTORS AND OFFICERS OF SURVIVING CORPORATION.

    (a)  The directors of  Sub shall be  the initial directors  of the Surviving
Corporation and shall hold office from the Effective Time until their respective
successors are duly elected or appointed and qualified in the manner provided in
the Certificate of Incorporation and By-Laws of the Surviving Corporation, or as
otherwise provided by law.

                                      A-1
<PAGE>
    (b) The officers of P-B at the Effective Time shall be the initial  officers
of the Surviving Corporation and shall hold office from the Effective Time until
removed  or until their respective successors  are duly elected or appointed and
qualified in the manner provided in the Certificate of Incorporation and By-Laws
of the Surviving Corporation, or as otherwise provided by law.

                                  ARTICLE III
                              CONVERSION OF SHARES

    3.1  EXCHANGE RATIO.   At the  Effective Time, by virtue  of the Merger  and
without any action on the part of the holder thereof:

        (a) Subject to Section 3.4 hereof, each share of common stock, par value
    $1.00  per share ("P-B Common Stock"), of P-B that is issued and outstanding
    immediately prior to the Effective Time, together with any associated rights
    under the P-B  Rights Agreement  (as defined  in Section  5.23) (other  than
    shares of P-B Common Stock to be cancelled pursuant to Section 3.1(b)) shall
    be  converted at the  Effective Time into  the right to  receive 0.88 shares
    (the "Exchange  Ratio") of  common stock,  par value  $0.001 per  share,  of
    Nellcor  together  with the  corresponding  preferred stock  purchase rights
    associated with such shares of Nellcor  common stock in accordance with  the
    Nellcor  Rights Agreement  (as defined  in Section  4.2(b)) ("Nellcor Common
    Stock"). All references herein to Nellcor Common Stock, including the shares
    issuable in the Merger, shall be deemed to include the associated  preferred
    stock purchase rights except where the context otherwise clearly requires.

        At  the Effective  Time, all  such shares of  P-B Common  Stock shall no
    longer be outstanding and shall  automatically be cancelled and retired  and
    shall  cease to exist, and each certificate previously representing any such
    shares of P-B Common Stock (a "Certificate") shall thereafter represent  the
    right  to receive (i) the number of whole shares of Nellcor Common Stock and
    (ii) cash in lieu of fractional shares  into which the shares of P-B  Common
    Stock  represented  by  such  Certificate have  been  converted  pursuant to
    Section 3.2 and Section 3.4 hereof. Each Certificate shall be exchanged  for
    (i) certificates representing whole shares of Nellcor Common Stock, and (ii)
    cash in lieu of fractional shares, issued in consideration therefor upon the
    surrender  of  such Certificate  in accordance  with the  provisions hereof,
    without interest  thereon. If  prior to  the Effective  Time Nellcor  should
    split or combine the shares of Nellcor Common Stock, or pay a stock dividend
    or  other stock distribution in, or in exchange of, shares of Nellcor Common
    Stock, or engage in any similar transaction, then the Exchange Ratio will be
    appropriately  adjusted  to  reflect  such  split,  combination,   dividend,
    exchange or other distribution or similar transaction.

        (b)  Each share of P-B Common Stock held in the treasury of P-B and each
    share of  P-B Common  Stock held  by Nellcor  or any  subsidiary of  Nellcor
    immediately  prior to the Effective Time  shall be cancelled and retired and
    cease to exist, and  no shares of  Nellcor Common Stock  shall be issued  in
    exchange  therefor. All shares of  Nellcor Common Stock owned  by P-B or any
    subsidiary of P-B shall become treasury stock of Nellcor.

        (c) Each  share of  common stock,  $0.001 par  value per  share, of  Sub
    issued  and outstanding  immediately prior to  the Effective  Time shall, by
    virtue of  the Merger  and without  any action  on the  part of  the  holder
    thereof,  be  converted into  one  share of  common  stock of  the Surviving
    Corporation.

    3.2  EXCHANGE OF SHARES.

    (a) Prior to  the Effective Time,  Nellcor shall select,  and enter into  an
agreement (in form and substance reasonably satisfactory to P-B) with, a bank or
trust  company to act as Exchange Agent hereunder (the "Exchange Agent"). Within
a reasonable  period  of time  after  the  Effective Time,  Nellcor  shall  make
available,  and each holder  of shares of  P-B Common Stock  will be entitled to
receive upon  surrender to  the  Exchange Agent  of  one or  more  Certificates,
certificates representing the

                                      A-2
<PAGE>
number  of whole shares of  Nellcor Common Stock and  cash in lieu of fractional
shares into which such shares of P-B  Common Stock are converted in the  Merger.
The  shares of Nellcor  Common Stock into  which the shares  of P-B Common Stock
shall be converted  in the Merger  shall be deemed  to have been  issued at  the
Effective Time.

    (b) As soon as reasonably practicable after the Effective Time, the Exchange
Agent  shall mail to each holder  of record of P-B Common  Stock (i) a letter of
transmittal (which shall specify  that delivery shall be  effected, and risk  of
loss  and  title to  the  Certificates shall  pass,  only upon  delivery  of the
Certificates to the Exchange Agent and shall be in such form and have such other
provisions as Nellcor may reasonably specify)  and (ii) instructions for use  in
effecting  the  surrender  of  the  Certificates  in  exchange  for certificates
representing shares of Nellcor Common Stock. Upon surrender of a Certificate for
cancellation to the  Exchange Agent  together with such  letter of  transmittal,
duly  executed, the holder of  such Certificate shall be  entitled to receive in
exchange therefor (i) a certificate representing that number of whole shares  of
Nellcor Common Stock and (ii) a check representing the amount of cash in lieu of
fractional shares, if any, which such holder has the right to receive in respect
of  the Certificate  so surrendered pursuant  to the provisions  of this Article
III.

    (c) In  the event  that any  Certificate  shall have  been lost,  stolen  or
destroyed,  upon the making of an affidavit  of that fact by the person claiming
such Certificate to be lost, stolen or destroyed, Nellcor will issue or cause to
be issued in exchange for such lost, stolen or destroyed Certificate the  number
of  whole shares of Nellcor  Common Stock and cash  in lieu of fractional shares
into which the  shares of P-B  Common Stock represented  by the Certificate  are
converted  in the Merger  in accordance with this  Article III. When authorizing
such issuance in  exchange therefor,  Nellcor may, in  its discretion  and as  a
condition  precedent to  the issuance thereof,  require the owner  of such lost,
stolen or destroyed Certificate  to give Nellcor  a bond in such  sum as it  may
direct  as  indemnity, or  such other  form  of indemnity,  as it  shall direct,
against any  claim  that  may  be  made against  Nellcor  with  respect  to  the
Certificate alleged to have been lost, stolen or destroyed.

    3.3  DIVIDENDS; TRANSFER TAXES.  No dividends that are declared on shares of
Nellcor  Common Stock after the Effective Time  will be paid to persons entitled
to receive certificates representing shares  of Nellcor Common Stock until  such
persons  surrender their Certificates. Upon such  surrender, there shall be paid
to the person in whose name the certificates representing such shares of Nellcor
Common Stock shall be issued, any dividends which shall have become payable with
respect to such shares  of Nellcor Common Stock  between the Effective Time  and
the  time of such  surrender. In no  event shall the  person entitled to receive
such dividends  be  entitled to  receive  interest  on such  dividends.  If  any
certificates  for any shares of Nellcor Common Stock  are to be issued in a name
other than that  in which the  Certificate surrendered in  exchange therefor  is
registered,  it shall be a condition of such exchange that the person requesting
such exchange shall (i) pay  to the Exchange Agent  any transfer or other  taxes
required  by reason of the  issuance of certificates for  such shares of Nellcor
Common Stock  in  a  name other  than  that  of the  registered  holder  of  the
Certificate  surrendered or (ii)  establish to the  satisfaction of the Exchange
Agent that such tax has been paid or is not applicable. Notwithstanding anything
in this Agreement  to the  contrary, neither the  Exchange Agent  nor any  party
hereto  shall be liable to a holder of shares of P-B Common Stock for any shares
of Nellcor Common Stock or dividends thereon or, in accordance with Section  3.4
hereof,  the  cash  payment  for fractional  interests,  delivered  to  a public
official pursuant to applicable escheat laws.

    3.4  NO  FRACTIONAL SHARES.   No fractional shares  of Nellcor Common  Stock
shall  be issued  pursuant to the  Merger. In lieu  of the issuance  of any such
fractional  share  of  Nellcor  Common  Stock  pursuant  to  Section  3.2,  cash
adjustments  will  be paid  to holders  in  respect of  any fractional  share of
Nellcor Common  Stock that  would  otherwise be  issuable.  The amount  of  such
adjustment  shall be the product  of such fraction of  a share of Nellcor Common
Stock multiplied by the closing sales price per share of Nellcor Common Stock on
the Nasdaq National Market on the business day immediately preceding the Closing
Date.

                                      A-3
<PAGE>
    3.5   CLOSING OF  P-B TRANSFER  BOOKS.   At the  Effective Time,  the  stock
transfer  books of P-B shall  be closed and no transfer  of shares of P-B Common
Stock shall thereafter be made. If,  after the Effective Time, Certificates  are
presented  to the Surviving  Corporation, they shall  be cancelled and exchanged
for certificates representing shares of Nellcor Common Stock or cash in lieu  of
fractional  shares  in  accordance  with  the terms  hereof.  At  and  after the
Effective Time, the holders of  shares of P-B Common  Stock to be exchanged  for
shares  of Nellcor Common Stock  pursuant to this Agreement  shall cease to have
any rights as stockholders of P-B, except for the right to surrender such  stock
certificates  in  exchange  for  shares  of  Nellcor  Common  Stock  as provided
hereunder.

    3.6   CLOSING.    The  closing of  the  transactions  contemplated  by  this
Agreement  (the  "Closing")  shall  take  place at  the  offices  of  Morrison &
Foerster, 345 California Street, San  Francisco, California 94104 at 9:00  a.m.,
local  time, on the first  business day (the "Closing  Date") after the later of
(a) the date on which both  P-B's and Nellcor's stockholders' meetings  referred
to  in Section 7.4 hereof shall  have occurred, and (b) the  day on which all of
the conditions set forth in Article VIII  hereof are satisfied or waived, or  at
such other date, time and place as Nellcor and P-B shall agree.

    3.7   SUPPLEMENTARY ACTION.   If at  any time after  the Effective Time, any
further assignments or assurances  in law or any  other things are necessary  or
desirable  to  vest  or  to  perfect  or  confirm  of  record  in  the Surviving
Corporation the title to  any property or  rights of either P-B  or the Sub,  or
otherwise  to  carry out  the  provisions of  this  Agreement, the  officers and
directors of the Surviving  Corporation are hereby  authorized and empowered  on
behalf  of P-B and  Sub, in the  name of and on  behalf of either  P-B or Sub as
appropriate, to execute and  deliver any and all  things necessary or proper  to
vest  or to perfect or confirm title to such property or rights in the Surviving
Corporation, and otherwise  to carry  out the  purposes and  provisions of  this
Agreement.

                                   ARTICLE IV
               REPRESENTATIONS AND WARRANTIES OF NELLCOR AND SUB

    Except as set forth in the disclosure letter delivered to P-B at or prior to
the  execution of  this Agreement  ("Nellcor Disclosure  Schedule"), Nellcor and
Sub, jointly and severally, represent and warrant to P-B as follows:

    4.1   ORGANIZATION.    Nellcor  is a  corporation  duly  organized,  validly
existing  and in good standing  under the laws of the  State of Delaware and has
the corporate power  to carry  on its  business as  it is  now being  conducted.
Nellcor  is duly qualified  as a foreign  corporation to do  business, and is in
good standing  (to the  extent the  concept of  good standing  exists), in  each
jurisdiction  where the character of its properties owned or held under lease or
the nature of its  activities makes such  qualification necessary, except  where
the failure to be so qualified will not in the aggregate have a Material Adverse
Effect.  Each subsidiary  of Nellcor  is a  corporation duly  organized, validly
existing and  in good  standing (to  the  extent the  concept of  good  standing
exists) under the laws of its jurisdiction of incorporation or organization, has
the corporate power to carry on its business as it is now being conducted and is
duly  qualified  to do  business, and  is in  good standing  (to the  extent the
concept of good standing  exists), in each jurisdiction  where the character  of
its  properties owned or held under lease  or the nature of its activities makes
such qualification necessary, except where the failure to be so duly  organized,
validly  existing and in good standing, to have such corporate power or to be so
qualified will not in the aggregate have a Material Adverse Effect. Nellcor  has
delivered  to P-B or its counsel complete  and correct copies of its Certificate
of Incorporation and Bylaws. Sub has not engaged in any business since the  date
of its incorporation other than as contemplated hereby.

    As  used in  this Agreement, (i)  the term "Material  Adverse Effect" means,
with respect to P-B or Nellcor, as the case may be, a material adverse effect on
the business, assets,  results of  operation or  financial condition  of P-B  or
Nellcor,  in each case  including its subsidiaries  taken as a  whole, or in its
ability to perform its obligations hereunder and (ii) the word "subsidiary" when
used with respect  to any  party means  any corporation  or other  organization,
whether  incorporated  or  unincorporated,  of which  such  party  or  any other
subsidiary  of  such  party  is   a  general  partner  (excluding   partnerships

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the  general partnership interests of which held by such party or any subsidiary
of such  party  do  not  have  a  majority  of  the  voting  interests  in  such
partnership)  or  of  which at  least  a  majority of  the  securities  or other
interests having by their terms ordinary voting power to elect a majority of the
Board of Directors or others performing  similar functions with respect to  such
corporations   or  other  organizations  is  directly  or  indirectly  owned  or
controlled by such party and/or by any one or more of the subsidiaries.

    4.2  CAPITALIZATION.

    (a) As of April 30, 1995,  the authorized capital stock of Nellcor  consists
of  50,000,000 shares of Nellcor Common Stock, and 5,000,000 shares of Preferred
Stock, par value $0.001 per share  (the "Nellcor Preferred Stock"). As of  April
30, 1995, 16,608,507 shares of Nellcor Common Stock were issued and outstanding,
stock  options  to  acquire  2,234,133  shares  of  Nellcor  Common  Stock  were
outstanding under all  stock option  plans of  Nellcor, no  warrants to  acquire
shares  of Nellcor Common Stock were outstanding, no shares of Nellcor Preferred
Stock were issued and  outstanding, and 2,463,528  additional shares of  Nellcor
Common  Stock (under Nellcor's stock option plans) and 500,000 shares of Nellcor
Preferred Stock were reserved  for issuance. No  changes in such  capitalization
have  occurred since April 30, 1995 that, in the aggregate, would be material to
Nellcor, except for option exercises in the ordinary course of business. All  of
the  issued and outstanding  shares of Nellcor Common  Stock are validly issued,
fully paid,  nonassessable  and free  of  preemptive rights  or  similar  rights
created  by statute, the  Certificate of Incorporation or  By-Laws of Nellcor or
any agreement to which Nellcor or any of its subsidiaries is a party or by which
Nellcor or any of  its subsidiaries is bound.  Since December 31, 1994,  Nellcor
has  not issued  any shares of  its capital  stock, except upon  the exercise of
stock options  to acquire  shares of  Nellcor Common  Stock to  employees  under
employee  benefit plans. All of  the shares of Nellcor  Common Stock issuable in
exchange for shares  of Common Stock  at the Effective  Time in accordance  with
this  Agreement will be, when so  issued, duly authorized, validly issued, fully
paid and nonassessable.

    (b) Except as described in Section 4.2(b) of the Nellcor Disclosure Schedule
and as set forth above and pursuant  to Nellcor's employee benefit plans and  as
otherwise  provided in  this Agreement and  that certain  Rights Agreement dated
September 1,  1992 between  Nellcor and  The First  National Bank  of Boston  as
Rights  Agent (the "Nellcor  Rights Agreement"), there  are not now,  and at the
Effective Time there will not be, any shares of capital stock of Nellcor  issued
or   outstanding  or  any  options,   warrants,  subscriptions,  calls,  rights,
convertible securities or other agreements or commitments obligating Nellcor  to
issue,  transfer or sell any shares of its capital stock. As of the date hereof,
no bonds, debentures, notes or other  indebtedness having the right to vote  (or
convertible  into or exercisable for securities having the right to vote) on any
matters on which stockholders  may vote ("Voting Debt")  of Nellcor were  issued
and  outstanding and  none will  be outstanding  as of  the Effective  Time. All
outstanding shares of the  capital stock of  Nellcor's subsidiaries are  validly
issued,  fully  paid,  non-assessable  and  owned  by  Nellcor  or  one  of  its
subsidiaries  free  and  clear  of   any  liens,  security  interest,   pledges,
agreements, claims, charges, or encumbrances of any nature whatsoever. There are
no  voting trust  or other  agreements or understandings  to which  Nellcor is a
party with respect to the voting of the  capital stock of Nellcor or any of  its
subsidiaries.  Except as described  in Section 4.2(b)  of the Nellcor Disclosure
Schedule, none of Nellcor or its subsidiaries is required to redeem,  repurchase
or  otherwise  acquire  shares  of  capital stock  of  Nellcor,  or  any  of its
subsidiaries, respectively, as a result of the transactions contemplated by this
Agreement. Except for options and warrants described above or as contemplated by
Section 7.8 and Section 7.14 below, and except as described in Section 4.2(b) of
the Nellcor Disclosure  Schedule, immediately  after the  Effective Time,  there
will  be no option, warrant, call, right  or agreement obligating Nellcor or any
subsidiary of  Nellcor  to  issue, deliver  or  sell,  or cause  to  be  issued,
delivered  or sold, any  shares of Nellcor  Common Stock or  any Voting Debt, or
obligating Nellcor or any subsidiary of Nellcor to grant, extend, or enter  into
any such option, warrant, call, right or agreement.

                                      A-5
<PAGE>
    (c)  The authorized capital  stock of Sub  consists of 100  shares of Common
Stock, $0.001 par value per  share, 100 shares of  which are validly issued  and
outstanding, fully paid and nonassessable and are owned by Nellcor.

    4.3   AUTHORITY RELATIVE TO THIS AGREEMENT.  Each of Nellcor and Sub has the
corporate power to enter  into this Agreement and  to carry out its  obligations
hereunder.  The execution and delivery of this  Agreement by Nellcor and Sub and
the consummation by Nellcor and Sub of the transactions contemplated hereby have
been duly authorized  by the  Boards of  Directors of  Nellcor and  Sub, and  by
Nellcor  as the sole stockholder  of Sub, and no  other corporate proceedings on
the part  of Nellcor  or Sub  are necessary  to approve  this Agreement  or  the
transactions  contemplated  hereby. This  Agreement  has been  duly  and validly
executed and delivered by each  of Nellcor and Sub  and constitutes a valid  and
binding  agreement of each  of Nellcor and Sub,  enforceable against Nellcor and
Sub in accordance with its terms.

    4.4  CONSENTS AND APPROVALS; NO VIOLATIONS.  Except as described in  Section
4.4  of the Nellcor Disclosure Schedule,  and except for applicable requirements
of the Hart-Scott-Rodino Antitrust Improvements Act of 1976 (the "HSR Act"), the
Securities Act  of  1933, as  amended  (the "Securities  Act"),  the  Securities
Exchange  Act of 1934,  as amended (the  "Exchange Act"), state  or foreign laws
relating to takeovers, if applicable, state securities or blue sky laws, and the
filing and recordation of a  Certificate of Merger as  required by the DGCL,  no
filing with, and no permit, authorization, consent or approval of, any public or
governmental  body or authority is necessary for the consummation by Nellcor and
Sub of the transactions contemplated by  this Agreement, except where a  failure
to  make  such filing  or to  obtain  such permit,  registration, authorization,
consent or approval will  not in the aggregate  have a Material Adverse  Effect.
Except  as described in Section 4.4  of the Nellcor Disclosure Schedule, neither
the execution  and  delivery  of this  Agreement  by  Nellcor or  Sub,  nor  the
consummation  by Nellcor  or Sub  of the  transactions contemplated  hereby, nor
compliance by Nellcor or Sub with any of the provisions hereof, will (a)  result
in  any breach of the Certificate of  Incorporation or By-Laws of Nellcor or any
of its subsidiaries, (b) result in a violation or breach of, or constitute (with
or without due notice or lapse of time  or both) a default (or give rise to  any
right  of termination, cancellation, acceleration or change in the award, grant,
vesting or determination) under, or give  rise to creation of any lien,  charge,
security  interest  or encumbrance  upon, any  of  the respective  properties or
assets of Nellcor or any of its subsidiaries under, any of the terms, conditions
or provisions of any  note, bond, mortgage, indenture,  deed of trust,  license,
contract,  lease, agreement,  arrangement or  other instrument  or obligation to
which Nellcor or any of its subsidiaries is  a party or by which any of them  or
any  of their properties or assets may be  bound or (c) violate any order, writ,
injunction, decree, statute, rule  or regulation applicable  to Nellcor, any  of
its  subsidiaries or any  of their properties  or assets, except  in the case of
clauses  (b)  and  (c)  for   violations,  breaches,  defaults  (or  rights   of
termination,  cancellation,  acceleration or  change), liens,  charges, security
interests or  encumbrances which  would not  in the  aggregate have  a  Material
Adverse Effect.

    4.5    REPORTS AND  FINANCIAL  STATEMENTS.   Nellcor  has filed  all reports
required to be  filed with the  Securities and Exchange  Commission (the  "SEC")
pursuant  to the Exchange Act since  July 7, 1984 including, without limitation,
an Annual Report  on Form 10-K  for the year  ended July 3,  1994 and  Quarterly
Reports on Form 10-Q for the quarters ended October 2, 1994, January 1, 1995 and
April  2, 1995 (all such reports,  collectively, the "Nellcor SEC Reports"), and
has previously furnished or  made available to P-B  true and complete copies  of
all  Nellcor SEC Reports filed with  respect to periods beginning after December
31, 1991 (including any exhibits thereto)  and will promptly deliver to P-B  any
Nellcor  SEC Reports filed between the date  hereof and the Effective Time. None
of such Nellcor SEC  Reports, as of their  respective dates (as amended  through
the  date hereof), contained or,  with respect to the  Nellcor SEC Reports filed
after the date hereof, will contain any  untrue statement of a material fact  or
omitted or, with respect to the Nellcor SEC Reports filed after the date hereof,
will omit to state a material fact required to be stated therein or necessary to
make the statements therein, in light of the circumstances under which they were
made,  not misleading. Each of the  balance sheets (including the related notes)
included  in  the   Nellcor  SEC  Reports   fairly  presents  the   consolidated

                                      A-6
<PAGE>
financial  position of Nellcor and its subsidiaries  as of the date thereof, and
the other  related statements  (including the  related notes)  included  therein
fairly  present  the results  of operations  and  the changes  in cash  flows of
Nellcor and its subsidiaries for the  respective periods set forth therein,  all
in conformity with generally accepted accounting principles consistently applied
during  the periods involved, except as  otherwise noted therein and subject, in
the case  of the  unaudited  interim financial  statements, to  normal  year-end
adjustments which would not in the aggregate be material in amount or effect.

    4.6   ABSENCE  OF CERTAIN  CHANGES OR  EVENTS.   Except as  disclosed in the
Nellcor SEC Reports filed  prior to the  date of this  Agreement, since July  3,
1994,  neither Nellcor  nor any of  its subsidiaries  has: (a) taken  any of the
actions set forth in Sections 6.1(b), 6.1(c) or 6.1(e) hereof; (b) incurred  any
material  liability, except in  the ordinary course  of its business, consistent
with past  practices;  (c)  suffered  any  change,  or  any  event  involving  a
prospective  change, in its business, assets,  financial condition or results of
operation which has had,  or is reasonably  likely to have,  in the aggregate  a
Material  Adverse Effect (other than as a  result of changes or proposed changes
in federal or state  health care (including health  care reimbursement) laws  or
regulations  of  general applicability  or  interpretations thereof,  changes in
generally accepted  accounting  principles and  changes  that could,  under  the
circumstances,  reasonably have been anticipated in light of disclosures made in
writing by Nellcor  to P-B prior  to the  execution of this  Agreement); or  (d)
subsequent  to  the date  hereof,  except as  permitted  by Section  6.1 hereof,
conducted its  business and  operations other  than in  the ordinary  course  of
business and consistent with past practices.

    4.7    INFORMATION  IN  REGISTRATION STATEMENT  AND  PROXY  STATEMENT.   The
information relating to Nellcor and its subsidiaries to be contained in (a)  the
Registration Statement on Form S-4 to be filed with the SEC by Nellcor under the
Securities Act for the purpose of registering the shares of Nellcor Common Stock
to  be issued  in the  Merger or pursuant  to this  Agreement (the "Registration
Statement") and (b) the  joint proxy statement to  be distributed in  connection
with  Nellcor's and P-B's  meetings of stockholders to  vote upon this Agreement
(the "Proxy Statement"),  will not contain  any untrue statement  of a  material
fact  or  omit to  state  any material  fact required  to  be stated  therein or
necessary in order to make the statements therein, in light of the circumstances
under which they are made, not misleading.

    4.8  LITIGATION.  As of the  date of this Agreement, except as disclosed  in
the  Nellcor SEC Reports filed prior to the date of this Agreement and except to
the extent that in the aggregate they would not reasonably be expected to have a
Material  Adverse  Effect:   (i)  there   is  no  action,   suit,  judicial   or
administrative  proceeding, arbitration or investigation pending or, to the best
knowledge of Nellcor,  threatened against  or involving  Nellcor or  any of  its
subsidiaries,   or  any  of  their  properties  or  rights,  before  any  court,
arbitrator, or administrative or governmental  body; (ii) there is no  judgment,
decree,  injunction,  rule  or  order  of  any  court,  governmental department,
commission, agency, instrumentality or arbitrator outstanding against Nellcor or
any of  its subsidiaries;  and (iii)  Nellcor and  its subsidiaries  are not  in
violation  of  any  term  of  any  judgments,  decrees,  injunctions  or  orders
outstanding against them.

    4.9  CONTRACTS.

    (a)  Each  of  the   contracts,  instruments,  mortgages,  notes,   security
agreements,  leases, agreements or  understandings, whether written  or oral, to
which Nellcor or any of its subsidiaries  is a party that relates to or  affects
the  assets or  operations of  Nellcor or  any of  its subsidiaries  or to which
Nellcor or any of its subsidiaries or their respective assets or operations  may
be  bound or subject  is a valid and  binding obligation of  Nellcor and in full
force and effect with respect to Nellcor or such subsidiary and, to the best  of
Nellcor's knowledge, with respect to all other parties thereto, except for where
the  failure to be valid, binding and in  full force and effect would not in the
aggregate have  a  Material  Adverse  Effect. Except  to  the  extent  that  the
consummation  of the transactions contemplated by this Agreement may require the
consent of third parties, there  are no existing defaults  by Nellcor or any  of
its  subsidiaries thereunder or, to the knowledge of Nellcor, by any other party

                                      A-7
<PAGE>
thereto, which defaults in the aggregate  would have a Material Adverse  Effect;
and  no event  of default  has occurred, and  no event,  condition or occurrence
exists, that (whether with or without notice, lapse of time, the declaration  of
default  or other similar event) would constitute a default by Nellcor or any of
its subsidiaries thereunder, other than defaults that would not in the aggregate
have a  Material  Adverse  Effect.  Section 4.9(a)  of  the  Nellcor  Disclosure
Schedule  lists all consents  of third parties required  for the consummation of
the transactions contemplated by this  Agreement, other than consents which  the
failure to obtain would not in the aggregate have a Material Adverse Effect.

    (b)  Except  (A) as  set forth  in  the Nellcor  SEC Reports  (including the
exhibits thereto) filed prior to the date of this Agreement, (B) as set forth in
Section 4.9(b) of the  Nellcor Disclosure Schedule, and  (C) for this  Agreement
and  other  agreements  that are  not  in  the aggregate  material  to Nellcor's
business, as  of the  date of  this Agreement  neither Nellcor  nor any  of  its
subsidiaries  is a party to  any oral or written  (i) consulting agreement, (ii)
joint venture, (iii) noncompetition or similar agreement that restricts  Nellcor
or its subsidiaries from engaging in a line of business, (iv) agreement with any
executive officer or other employee of Nellcor or any subsidiary the benefits of
which  are contingent, or the terms of which are altered, upon the occurrence of
a transaction involving Nellcor of the nature contemplated by this Agreement, or
(v) agreement with respect to any executive officer of Nellcor or any subsidiary
providing any term of employment or  compensation guaranty. Except as set  forth
in  Section 4.9(b) of the Nellcor  Disclosure Schedule, Nellcor has no agreement
or plan,  including  any stock  option  plan, stock  appreciation  rights  plan,
restricted  stock plan or stock purchase plan, any of the benefits of which will
be increased, or the vesting  of the benefits of  which will be accelerated,  by
the  occurrence of any of the transactions contemplated by this Agreement or the
value of any of the benefits of which will be calculated on the basis of any  of
the transactions contemplated by this Agreement.

    (c)  Except  as  set  forth  in Section  4.9(c)  of  the  Nellcor Disclosure
Schedule, Nellcor has no agreements or arrangements to sell or otherwise dispose
of, or lease, acquire or otherwise invest in, any property, lines of business or
other assets that  are in the  aggregate material to  Nellcor's business,  other
than  agreements and arrangements for such sale, disposition, lease, acquisition
or investment that are in the ordinary course of Nellcor's business.

    4.10  EMPLOYEE BENEFIT PLANS.

    (a) Section 4.10 of  the Nellcor Disclosure Schedule  sets forth a true  and
complete list of each material written or oral employee benefit plan (including,
without  limitation, any "employee  benefit plan" as defined  in Section 3(3) of
the Employee  Retirement Income  Security Act  of 1974,  as amended  ("ERISA")),
policy  or agreement (including, without limitation, any employment agreement or
severance agreement)  that is  maintained (all  of the  foregoing, the  "Nellcor
Plans"),  or is or was contributed to by Nellcor or pursuant to which Nellcor is
still potentially  liable for  payments,  benefits or  claims.  A copy  of  each
Nellcor  Plan as currently in effect and,  if applicable, the most recent Annual
Report, Actuarial Report or Valuation, Summary Plan Description, Trust Agreement
and a  Determination  Letter  issued by  the  IRS  for each  Nellcor  Plan  have
heretofore  been delivered to P-B or its  counsel. Neither Nellcor nor any trade
or business, whether or not incorporated (an "ERISA Affiliate"), which  together
with  Nellcor would be deemed a "single  employer" within the meaning of Section
4001 of ERISA, has maintained or contributed to any plan subject to Title IV  of
ERISA or Section 412 of the Code (including any "multiemployer plan," as defined
in  Section 3(37) of ERISA ("Multiemployer Plan")) during the six calendar years
preceding the date of this Agreement.

    (b) Each Nellcor  Plan which is  an "employee benefit  plan", as defined  in
Section  3(3)  of  ERISA,  complies  by its  terms  and  in  operation  with the
requirements provided by any and all  statutes, orders or governmental rules  or
regulations  currently in effect  and applicable to  the Nellcor Plan, including
but not limited  to ERISA and  the Code, except  for instances of  noncompliance
that would not in the aggregate have a Material Adverse Effect.

                                      A-8
<PAGE>
    (c)  All reports, forms  and other documents  required to be  filed with any
government  entity  with  respect  to  any  Nellcor  Plan  (including,   without
limitation,  summary plan descriptions,  Forms 5500 and  summary annual reports)
have been timely filed and are  accurate, except for instances of  noncompliance
that would not in the aggregate have a Material Adverse Effect.

    (d)  Each Nellcor Plan intended to qualify  under Section 401(a) of the Code
has been determined by the Internal Revenue Service to so qualify after  January
1,  1985, and each trust maintained pursuant  thereto has been determined by the
Internal Revenue Service  to be exempt  from taxation under  Section 501 of  the
Code. Except as set forth in Section 4.10(d) of the Nellcor Disclosure Schedule,
nothing  has occurred since the date of the Internal Revenue Service's favorable
determination letter  that  could  adversely affect  the  qualification  of  any
Nellcor  Plan and related trust, except such adverse effects as would not in the
aggregate constitute a Material Adverse Effect. Nellcor and each ERISA Affiliate
of Nellcor have timely and properly  applied for a written determination by  the
Internal  Revenue Service on the qualification of each such Nellcor Plan and its
related trust under Section 401(a) of the Code, as amended by the Tax Reform Act
of 1986 and subsequent legislation enacted through the date hereof, and  Section
501 of the Code.

    (e)  Except  as  set forth  in  Section  4.10(e) of  the  Nellcor Disclosure
Schedule,  all  contributions  or  other  amounts  payable  by  Nellcor  or  its
subsidiaries  as of the Effective Time with  respect to each Nellcor Plan and in
respect of  current or  prior plan  years have  been or  will be  (prior to  the
Effective Time) either paid or accrued on the Financial Statements of Nellcor in
accordance with past practice and the recommended contribution in any applicable
actuarial report.

    (f) No Nellcor Plan provides benefits, including without limitation death or
medical  benefits (whether  or not insured),  with respect to  current or former
employees for periods extending beyond their retirement or other termination  of
service  (other than (i) continuation group  health coverage pursuant to Section
4980B of  the  Code,  (ii)  death benefits  or  retirement  benefits  under  any
"employee pension plan," as that term is defined in Section 3(2) of ERISA, (iii)
deferred  compensation benefits  with respect  to which  there is  an accrual of
liability on the  books of Nellcor  or its ERISA  Affiliates, (iv) benefits  the
full  cost of which  is borne by the  current or former employee  (or his or her
beneficiary),  (v)  benefits  set  forth  in  Section  4.10(f)  of  the  Nellcor
Disclosure  Schedule or (vi) benefits which in the aggregate are not material to
Nellcor's business).

    (g) All  insurance  premiums  (including premiums  to  the  Pension  Benefit
Guaranty   Corporation)  have  been  paid  in   full,  subject  only  to  normal
retrospective adjustments in  the ordinary  course, with regard  to the  Nellcor
Plans  for plan years ending on or  before the date hereof, except for instances
of non-payment that would not in the aggregate have a Material Adverse Effect.

    (h) As of the  date hereof, except  as set forth in  Section 4.10(h) of  the
Nellcor  Disclosure Schedule, no Nellcor Plan subject  to Title IV of ERISA, and
no employee benefit plan maintained by an ERISA Affiliate of Nellcor and subject
to Title IV of ERISA, has benefit liabilities (as defined in Section 4001(a)(16)
of ERISA) exceeding the assets of such plan or has been completely or  partially
terminated.

    (i)  Except  as  set forth  in  Section  4.10(i) of  the  Nellcor Disclosure
Schedule and except for prohibited  transactions, reportable events and  actions
or  claims as would  not in the  aggregate have a  Material Adverse Effect, with
respect to each Nellcor Plan:

        (1) no prohibited  transactions (as  defined in  Section 406  or 407  of
    ERISA  or Section  4975 of  the Code)  have occurred  for which  a statutory
    exemption is not available;

        (2) no  reportable event  (as  defined in  Section  4043 of  ERISA)  has
    occurred as to which a notice would be required to be filed with the Pension
    Benefit Guaranty Corporation;

        (3)  no action or claims (other than routine claims for benefits made in
    the ordinary course  of Plan  administration for  which Plan  administrative
    review  procedures have not been exhausted) are pending or, to the knowledge
    of  Nellcor,  threatened  or  imminent  against  or  with  respect  to   the

                                      A-9
<PAGE>
    Nellcor Plan, any employer who is participating (or who has participated) in
    any  Plan or any  fiduciary (as defined  in Section 3(21)  of ERISA), of the
    Plan, except for actions or  claims that would not  in the aggregate have  a
    Material Adverse Effect; and

        (4)  neither Nellcor  nor any fiduciary  has any knowledge  of any facts
    which could give rise to any such action or claim.

    (j)  Neither Nellcor nor any ERISA Affiliate of Nellcor has any liability or
is threatened  with  any  liability  (whether joint  or  several)  (i)  for  the
termination  of any single employer plan under Sections 4062 or 4064 of ERISA or
any multiple  employer plan  under Section  4063  of ERISA,  (ii) for  any  lien
imposed  under Section 302(f) of ERISA or  Section 412(n) of the Code, (iii) for
any interest payments required under Section  302(e) of ERISA or Section  412(m)
of  the Code, (iv) for any excise tax imposed by Sections 4971, 4975, 4976, 4977
or 4979 of  the Code, (v)  for any minimum  funding contributions under  Section
302(c)(11)  of ERISA  or Section 412(c)(11)  of the  Code, (vi) to  a fine under
Section 502 of ERISA, or (vii) for any transaction within the meaning of Section
4069 of ERISA, except in  each case for such liabilities  that would not in  the
aggregate have a Material Adverse Effect.

    (k)  Nellcor has not  incurred any withdrawal liability  with respect to any
Multiemployer Plan within the meaning of  Sections 4201 and 4204 of ERISA  which
would  in the aggregate have a Material Adverse Effect, and no liabilities exist
with respect to  withdrawals from  any Multiemployer Plans  which could  subject
Nellcor  to any controlled group liability  under Section 4001(b) of ERISA which
would in the aggregate have a Material Adverse Effect.

    (l) All of the Nellcor Plans,  to the extent applicable, are in  substantial
compliance  with the continuation of  group health coverage provisions contained
in Section 4980B of the Code and  Sections 601 through 608 of ERISA, except  for
such  instances of noncompliance that would not in the aggregate have a Material
Adverse Effect.

    4.11   TAX  MATTERS.    Nellcor  makes  the  following  representations  and
warranties with respect to tax matters.

    (a)    DEFINITIONS.    For  purposes of  this  Section  4.11,  the following
definitions shall apply:

        (1) The term "Nellcor Group" shall mean, individually and  collectively,
    (i)  Nellcor and (ii) any individual, trust, corporation, partnership or any
    other entity  as to  which Nellcor  is  liable for  Taxes incurred  by  such
    individual  or  entity  either  as a  transferee,  or  pursuant  to Treasury
    Regulations Section 1.1502-6, or pursuant to any other provision of federal,
    territorial, state, local or foreign law or regulations.

        (2)  The  term  "Taxes"  shall  mean  all  taxes,  however  denominated,
    including  any interest, penalties or other additions to tax that may become
    payable in  respect thereof,  imposed by  any federal,  territorial,  state,
    local  or foreign government  or any agency or  political subdivision of any
    such government, which taxes shall include, without limiting the  generality
    of  the foregoing, all  income or profits taxes  (including, but not limited
    to, federal  income taxes  and  state income  taxes), payroll  and  employee
    withholding  taxes, unemployment insurance, social security taxes, sales and
    use taxes, ad valorem taxes,  excise taxes, franchise taxes, gross  receipts
    taxes,  business license taxes, occupation taxes, real and personal property
    taxes, stamp taxes, transfer  taxes, workers' compensation, Pension  Benefit
    Guaranty  Corporation  premiums and  other  governmental charges,  and other
    obligations of the  same or of  a similar  nature to any  of the  foregoing,
    which the Nellcor Group is required to pay, withhold or collect.

        (3)  The term "Returns" shall  mean all reports, estimates, declarations
    of estimated  tax,  information  statements  and  returns  relating  to,  or
    required  to be filed  in connection with,  any Taxes, including information
    returns or reports with respect to backup withholding and other payments  to
    third parties.

    (b)   RETURNS FILED AND  TAXES PAID.  Except  for instances of noncompliance
that would not in the aggregate have a Material Adverse Effect, (i) all  Returns
required to be filed by or on behalf of

                                      A-10
<PAGE>
members  of the Nellcor  Group have been duly  filed on a  timely basis and such
Returns are true, complete and  correct, (ii) all Taxes  shown to be payable  on
the  Returns or on subsequent assessments with respect thereto have been paid in
full on a  timely basis, and  (iii) no other  Taxes are payable  by the  Nellcor
Group  with respect to items or periods  covered by such Returns (whether or not
shown on or reportable on such Returns)  or with respect to any period prior  to
the date of this Agreement. Except for instances of noncompliance that would not
in  the aggregate  have a  Material Adverse Effect,  each member  of the Nellcor
Group has withheld and paid  over all Taxes required  to have been withheld  and
paid  over, and complied  with all information  reporting and backup withholding
requirements, including maintenance of required records with respect thereto, in
connection with amounts  paid or  owing to any  employee, creditor,  independent
contractor,  or  other third  party.  Except for  liens  that would  not  in the
aggregate have a  Material Adverse  Effect, there  are no  liens on  any of  the
assets  of any  member of the  Nellcor Group  with respect to  Taxes, other than
liens for Taxes  not yet  due and  payable or  for Taxes  that a  member of  the
Nellcor  Group is contesting  in good faith  through appropriate proceedings and
for which appropriate reserves have been established.

    (c)  TAX RESERVES.  The amount  of Nellcor's liability for unpaid Taxes  for
all  periods ending  on or  before the date  of this  Agreement does  not in the
aggregate exceed  the  amount  of  the  current  liability  accruals  for  Taxes
(excluding  reserves for deferred Taxes), as  such accruals are reflected on the
consolidated balance sheet of Nellcor included in the Nellcor SEC Report for the
quarter ending  closest  to  the date  of  this  Agreement, and  the  amount  of
Nellcor's  liability for unpaid  Taxes for all  periods ending on  or before the
Effective Time  shall not  in the  aggregate exceed  the amount  of the  current
liability  accruals for Taxes  (excluding reserves for  deferred Taxes), as such
accruals are reflected on the consolidated balance sheet of Nellcor included  in
the  Nellcor SEC Report  for the quarter  ending closest to  the Effective Time,
except (as to all matters covered by  this Section 4.11(c)) for any excess  that
does not in the aggregate have a Material Adverse Effect.

    (d)  CONSOLIDATED RETURNS FURNISHED.  P-B has been furnished by Nellcor true
and complete copies of (i) income tax audit reports, statements of deficiencies,
closing  or other agreements  received by the Nellcor  Group relating to federal
income taxes and (ii) all federal income  tax returns for the Nellcor Group,  in
each  case for all  periods ending on  and after December  31, 1991. Nellcor has
never been a  member of an  affiliated group filing  consolidated returns  other
than a group of which Nellcor was the common parent.

    (e)   TAX  DEFICIENCIES; AUDITS; STATUTES  OF LIMITATIONS.   No deficiencies
exist or  have  been  asserted  (either in  writing  or  verbally,  formally  or
informally)  or are expected to be asserted with respect to Taxes of the Nellcor
Group that  would cause  Nellcor's reserve  for taxes  to be  understated in  an
amount  material  to Nellcor.  Except  as disclosed  in  Section 4.11(e)  of the
Nellcor Disclosure Schedule, no federal income tax returns of the Nellcor  Group
are  currently  under  audit, and  no  waiver  or extension  of  the  statute of
limitations is in effect with respect to any federal income tax returns.

    (f)  TAX SHARING AGREEMENTS.  Nellcor is not (nor has it ever been) a  party
to any tax sharing agreement.

    (g)   SECTION 6038A COMPLIANCE.   Except for instances of noncompliance that
would not in the  aggregate have a Material  Adverse Effect and any  maintenance
agreements  that are not in  the aggregate material to  Nellcor: (i) Nellcor has
filed all reports  and has created  and/or retained all  records required  under
Section 6038A of the Code with respect to its ownership by and transactions with
related  parties; (ii) each related foreign  person required to maintain records
under Section 6038A with respect to transactions between Nellcor and the related
foreign person  has  maintained  such  records; (iii)  all  documents  that  are
required  to  be created  and/or preserved  by the  related foreign  person with
respect to transactions with Nellcor are either maintained in the United States,
or Nellcor is exempt from the  record maintenance requirements of Section  6038A
with  respect to such transactions  under Treasury Regulation section 1.6038A-1;
(iv) Nellcor  is  not a  party  to any  record  maintenance agreement  with  the
Internal  Revenue Service  with respect to  Section 6038A; and  (v) each related
foreign person  that has  engaged in  transactions with  Nellcor has  authorized
Nellcor to act as

                                      A-11
<PAGE>
its  limited agent solely for  purposes of Sections 7602,  7603, and 7604 of the
Code with respect  to any  request by the  Internal Revenue  Service to  examine
records  or produce testimony  related to any transaction  with Nellcor and each
such authorization remains in full force and effect.

    4.12  COMPLIANCE WITH  APPLICABLE LAW.  Except  as disclosed in the  Nellcor
SEC  Reports filed prior to the date of  this Agreement, Nellcor and each of its
subsidiaries holds  all licenses,  franchises, permits,  variances,  exemptions,
orders,  approvals and  authorizations necessary for  the lawful  conduct of its
business under and  pursuant to, and  the business  of each of  Nellcor and  its
subsidiaries  is  not being  conducted  in violation  of,  any provision  of any
federal, state,  local or  foreign statute,  law, ordinance,  rule,  regulation,
judgment,  decree,  order, concession,  grant, franchise,  permit or  license or
other governmental authorization or approval applicable to Nellcor or any of its
subsidiaries, except to the extent that  the failure to hold any such  licenses,
franchises, permits, variances, exemptions, orders, approvals or authorizations,
or  the  existence of  any such  violation, would  not in  the aggregate  have a
Material Adverse Effect.

    4.13  SUBSIDIARIES.  Exhibit 21 to Nellcor's most recent Form 10-K  included
in  the Nellcor SEC Reports lists all the subsidiaries of Nellcor as of the date
of this Agreement (except for Sub) and indicates for each such subsidiary as  of
such date the jurisdiction of incorporation or organization.

    4.14   SECTION 203  OF THE DGCL NOT  APPLICABLE.  The  Board of Directors of
Nellcor has approved the transactions contemplated by this Agreement pursuant to
Section 203(a)(1) of the DGCL such that the remaining provisions of Section  203
(assuming  the accuracy  of the representations  contained in  Section 5.16) are
thereby made inapplicable  to the  Merger and the  transactions contemplated  by
this Agreement.

    4.15  LABOR AND EMPLOYMENT MATTERS.

    (a)  Except for such matters that would not in the aggregate have a Material
Adverse Effect, (i) Nellcor and its subsidiaries are and have been in compliance
with all applicable laws respecting  employment and employment practices,  terms
and conditions of employment and wages and hours, including, without limitation,
the  Immigration  Reform and  Control Act  ("IRCA"),  the Worker  Adjustment and
Retraining Notification  Act  ("WARN"),  and  such  laws  respecting  employment
discrimination,  equal opportunity,  affirmative action,  worker's compensation,
occupational safety  and  health  requirements and  unemployment  insurance  and
related matters, and are not engaged in and have not engaged in any unfair labor
practice;  (ii) no investigation or review  by or before any governmental entity
concerning any violations  of any  such applicable laws  is pending  or, to  the
knowledge of Nellcor, threatened, nor has any such investigation occurred during
the  last seven  years, and  no governmental entity  has provided  any notice to
Nellcor or any of  its subsidiaries asserting an  intention to conduct any  such
investigation;  (iii) there  is no labor  strike, dispute,  slowdown or stoppage
actually pending or, to the knowledge of Nellcor, threatened against Nellcor  or
any  of  its  subsidiaries;  (iv)  no  union  representation  question  or union
organizational activity exists respecting the employees of Nellcor or any of its
subsidiaries;  and  (v)  neither  Nellcor  nor  any  of  its  subsidiaries   has
experienced any work stoppage or other labor difficulty.

    No collective bargaining agreement exists which is binding on Nellcor or any
of its subsidiaries.

    (b) Except for benefits provided under agreements and plans described in the
Nellcor SEC Reports or in Section 4.15(b) of the Nellcor Disclosure Schedule, in
the  event of  termination of  the employment  of any  of the  current officers,
directors, employees or agents  of Nellcor or any  of its subsidiaries,  neither
Nellcor,  any  of  its subsidiaries,  P-B,  the Surviving  Corporation,  nor any
subsidiaries of P-B,  will pursuant to  any agreement or  by reason of  anything
done prior to the Effective Time by Nellcor or any of its subsidiaries be liable
to any of said officers, directors, employees or agents for so-called "severance
pay"  or any other similar payments  or benefits, including, without limitation,
post-employment healthcare (other than pursuant to COBRA) or insurance benefits.

    4.16  OWNERSHIP  OF SHARES  OF P-B  COMMON STOCK.   As of  the date  hereof,
neither  Nellcor nor, to its knowledge, any  of its affiliates or associates (as
such terms are defined under the Exchange Act),

                                      A-12
<PAGE>
   
(i)  beneficially  owns,  directly  or  indirectly,  or  (ii)  is  party  to any
agreement, arrangement or understanding for  the purpose of acquiring,  holding,
voting or disposing of, in each case, shares of P-B Common Stock, except for (i)
shares  of P-B Common  Stock in the  aggregate representing less  than 1% of the
outstanding shares of P-B Common Stock  and (ii) the "standstill" provisions  of
the  Confidentiality Agreement dated March 1,  1995 between Nellcor and P-B (the
"Confidentiality Agreement") relating to acquisition of P-B Common Stock.
    

   
____4.17__INSURANCE.__As  of  the   date  hereof,  Nellcor   and  each  of   its
subsidiaries  are insured  by insurers reasonably  believed by Nellcor  to be of
recognized financial responsibility against  such losses and  risks and in  such
amounts  as  are customary  in the  businesses  in which  they are  engaged. All
material policies of insurance and fidelity or surety bonds insuring Nellcor  or
any  of  its subsidiaries  or  their respective  businesses,  assets, employees,
officers and directors  are in  full force and  effect. Except  as described  in
Section  4.17 of the Nellcor  Disclosure Schedule, as of  the date hereof, there
are no material  claims by Nellcor  or any  of its subsidiaries  under any  such
policy  or instrument as to which any  insurance company is denying liability or
defending under a reservation of rights clause.
    

   
____4.18__CONTRACTS  WITH   PHYSICIANS,   HOSPITALS,  HMOS   AND   THIRD   PARTY
PROVIDERS.__Nellcor  has made available to representatives  of P-B a list of all
outstanding contracts, partnerships,  joint ventures and  other arrangements  or
understandings  (written or  oral) that are  material to  Nellcor's business and
that are between (a) Nellcor or any  of its subsidiaries and (b) any  physician,
hospital,  HMO, other managed  care organization, or  other third-party provider
relating to the sale or supply of  medical devices, the provision of medical  or
consulting  services,  treatments  or  patient referrals  or  any  other similar
activities.
    

   
____4.19__ENVIRONMENTAL PROTECTION.
    
   
____(a)_None of Nellcor, Nellcor's  subsidiaries, or, to  the best of  Nellcor's
knowledge,  any Nellcor Property (as defined in sub-section (d) below) is or has
been in violation of  any federal, state or  local law, ordinance or  regulation
concerning  industrial hygiene  or environmental conditions,  including, but not
limited to, soil and groundwater  conditions ("Environmental Laws"), except  for
violations that would not in the aggregate have a Material Adverse Effect.
    

   
____(b)_Neither Nellcor nor any of its subsidiaries has reported any, or has had
knowledge  of any circumstances  giving rise to  any reporting requirement under
applicable Environmental Laws  as to any,  spills or releases  of any  Hazardous
Material  that would in  the aggregate have  a Material Adverse  Effect, nor has
Nellcor or any of its subsidiaries received any notices of spills or releases of
Hazardous Materials that would in the aggregate have a Material Adverse Effect.
    

   
____(c)_There is  no  proceeding  or  investigation  pending  or,  to  the  best
knowledge of Nellcor, threatened by any governmental entity or other person with
respect  to the  presence of Hazardous  Material on Nellcor's  Properties or the
migration thereof from or to other property  that would in the aggregate have  a
Material  Adverse Effect. Neither  Nellcor nor any of  its subsidiaries has ever
been required  by any  governmental  entity to  treat,  clean up,  or  otherwise
dispose  of, remove or neutralize any Hazardous  Material from or on any Nellcor
Property that would in the aggregate have a Material Adverse Effect.
    

   
____(d)_Neither Nellcor, any current  or former subsidiary  of Nellcor, nor  any
other  person has engaged in  any activity that might  reasonably be expected to
involve the generation, use, manufacture, treatment, transportation, storage  in
tanks  or otherwise, or disposal  of Hazardous Material on  or from any property
that Nellcor or any of its current or former subsidiaries now owns or leases  or
has  previously owned or leased  or in which Nellcor  or any such subsidiary now
holds or has previously held any  security interest, mortgage, or other lien  or
interest  ("Nellcor  Property") which  generation, use,  manufacture, treatment,
transportation, storage  or disposal  would  in the  aggregate have  a  Material
Adverse  Effect, and  no (i)  presence, release,  threatened release, discharge,
spillage or migration of Hazardous Material, (ii) condition that has resulted or
could result in any use, ownership  or transfer restriction, or (iii)  condition
of   actual  or  potential  nuisance  has  occurred  on  or  from  such  Nellcor
    

                                      A-13
<PAGE>
   
Property, and  no condition  exists that  could give  rise to  any suit,  claim,
action, proceeding or investigation by any person or governmental entity against
Nellcor, any of its subsidiaries or any other person or such Nellcor Property as
a  result of  or in  connection with (a)  any of  the foregoing  events, (b) any
failure to obtain any required permits or approvals of any governmental  entity,
(c)  the violation of any terms or conditions  of such permits, or (d) any other
violation of Environmental Laws; other than (as to all of the foregoing matters)
events, failures, violations or conditions that would not in the aggregate  have
a Material Adverse Effect.
    

   
____"Hazardous  Material"  shall mean  any substance,  chemical, waste  or other
material which is listed, defined or otherwise identified as hazardous, toxic or
dangerous under any applicable law; as well as any petroleum, petroleum  product
or  by-product, crude oil,  natural gas, natural  gas liquids, liquefied natural
gas, or synthetic  gas useable for  fuel, and "source,"  "special nuclear,"  and
"by-product"  material as defined  in the Atomic  Energy Act of  1954, 42 U.S.C.
SectionSection2011 ET SEQ.
    

   
____(e)_To  the  best  of  Nellcor's  knowledge,  there  are  no  substances  or
conditions  in or  on Nellcor  Property which  may support  claims or  causes of
action under any applicable Environmental Law, which claims or causes of  action
would in the aggregate have a Material Adverse Effect.
    

   
____(f)_For  purposes of this  Section 4.19, the  term "Material Adverse Effect"
includes (i) any material injunction or criminal action or proceeding against or
involving Nellcor and (ii) any requirement that executive officers of Nellcor or
P-B be subjected  to a  consent decree or  become individually  involved in  any
proceeding in clause (i) above.
    

   
____4.20__INTELLECTUAL PROPERTY RIGHTS.
    
   
____(a)_Section  4.20(a)  of  the  Nellcor  Disclosure  Schedule  sets  forth an
accurate and  complete  list  of  all (i)  patents,  applications  for  patents,
registrations  of trademarks (including service marks) and applications therefor
and registrations  of copyrights  and applications  therefor that  are owned  by
Nellcor  or any of Nellcor's subsidiaries and that are in the aggregate material
to Nellcor's business; (ii) other Intellectual Property Rights that are owned by
Nellcor or Nellcor's subsidiaries and that are in the aggregate material to  the
conduct  of  Nellcor's business;  (iii) unexpired  licenses relating  to Nellcor
Intellectual Property Rights (as defined below) that have been granted to or  by
Nellcor  or any of Nellcor's subsidiaries and that are in the aggregate material
to the conduct  of Nellcor's  business; and  (iv) other  agreements relating  to
Intellectual  Property Rights that are in  the aggregate material to the conduct
of Nellcor's business.
    

   
____(b)_To Nellcor's knowledge, Nellcor and Nellcor's subsidiaries  collectively
own  and  have the  right to  use, and  to  license others  to use,  all Nellcor
Intellectual Property Rights that are in  the aggregate material to the  conduct
of Nellcor's business. Such ownership and right to use, and to license others to
use,  are free and clear of, and without liability under, all liens and security
interests of third parties that would in the aggregate be material to  Nellcor's
business.  To  Nellcor's knowledge,  such  ownership and  right  to use,  and to
license others to use, are free and  clear of, and without liability under,  all
claims   and  rights  of  third  parties  that,  if  determined  to  be  legally
protectable, could in the aggregate have a Material Adverse Effect.
    

   
____(c)_Nellcor has taken reasonable steps sufficient to safeguard and  maintain
the  secrecy and  confidentiality of,  or Nellcor's  proprietary rights  in, the
unpatented know-how,  technology,  proprietary processes,  formulae,  and  other
information  that  is in  the  aggregate material  to  the conduct  of Nellcor's
business, including, without limitation,  the know-how, technology,  proprietary
processes,  formulae, and other  information listed as  trade secrets in Section
4.20(c) of the Nellcor Disclosure Schedule. Without limitation of the generality
of the foregoing,  to Nellcor's  knowledge, Nellcor  and Nellcor's  subsidiaries
have   obtained  confidentiality  and   inventions  assignment  agreements  from
substantially  all  Nellcor's  past   and  present  employees  and   independent
contractors  involved  in the  creation or  development of  Nellcor Intellectual
Property  Rights  (including,  without   limitation,  from  all  employees   and
contractors  who  are  inventors,  authors, creators  or  developers  of Nellcor
Intellectual Property Rights) that are in the aggregate material to the  conduct
of Nellcor's business.
    

                                      A-14
<PAGE>
   
____(d)_Except  for licenses listed in Section 4.20(d) of the Nellcor Disclosure
Schedule as royalty-bearing, there  are no royalties,  honoraria, fees or  other
payments  payable by Nellcor or Nellcor subsidiaries  to any person by reason of
the  ownership,  use,  license,  sale   or  disposition  of  any  of   Nellcor's
Intellectual  Property  Rights, which  Intellectual Property  Rights are  in the
aggregate material to the conduct of Nellcor's business.
    

   
____(e)_Neither Nellcor nor any of  Nellcor's subsidiaries (i) is infringing  in
the  conduct of Nellcor's business the right or claimed right of any other party
with respect to any Intellectual Property  Rights, or (ii) has knowledge of  any
alleged  or claimed infringement  by any product  or process manufactured, used,
sold or under  development by or  for Nellcor or  Nellcor's subsidiaries in  the
conduct  of Nellcor's business  that, if proven,  would in the  aggregate have a
Material Adverse Effect.
    

   
____(f)_To Nellcor's knowledge,  no independent contractors  who have  performed
services  related to  Nellcor's business  have any  right, title  or interest in
Nellcor's Intellectual Property Rights that  in the aggregate can be  reasonably
expected to have a Material Adverse Effect.
    

   
____(g)_The  execution, delivery and  performance of this  Agreement by Nellcor,
and the consummation by  Nellcor of the  transactions contemplated hereby,  will
not   breach,  violate  or  conflict  with  any  agreement  governing  Nellcor's
Intellectual Property Rights that are in  the aggregate material to the  conduct
of Nellcor's business, will not cause the forfeiture or termination or give rise
to a right of forfeiture or termination of Nellcor's Intellectual Property Right
or  in any way impair the right of  Nellcor to use, sell, license or dispose of,
or bring any  action for  the infringement of,  Nellcor's Intellectual  Property
Rights or portion thereof.
    

   
____(h)_For  purposes of this Section 4.20,  "use," with respect to Intellectual
Property Rights,  includes  make, reproduce,  display  or perform  (publicly  or
otherwise),  prepare derivative works  based on, sell,  distribute, disclose and
otherwise exploit such Intellectual  Property Rights and products  incorporating
or subject to such Intellectual Property Rights.
    

   
____(i)_As used in this Agreement, the term "Intellectual Property Rights" means
intellectual  property  rights, including,  without limitation,  patents, patent
applications, patent rights,  trademarks, trademark  applications, trade  names,
service  marks, service  mark applications,  copyrights, copyright applications,
publication rights,  computer programs  and other  computer software  (including
source codes and object codes), inventions, know-how, trade secrets, technology,
proprietary  processes  and formulae.  The  term "Nellcor  Intellectual Property
Rights" means all Intellectual Property Rights  that are part of the conduct  of
the business of Nellcor.
    

   
____(j)__Nellcor  has provided P-B with copies of all background information and
documents with respect  to the litigation  described at Section  4.20(j) of  the
Nellcor  Disclosure Schedule that  have been requested  by P-B and  that are not
subject to the attorney-client privilege.
    

   
____(k)_For purposes of  this Section  4.20, the  term "material"  when used  in
reference  to rights or agreements, shall mean  rights or agreements the loss or
impairment of which,  in the aggregate  could be reasonably  expected to have  a
Material Adverse Effect.
    

   
____4.21__FDA AND RELATED MATTERS.
    
   
____(a)_Section  4.21 of the  Nellcor Disclosure Schedule  sets forth a complete
and accurate list, referencing relevant records and documents, for the last five
years, of (i) all Regulatory or Warning Letters, Notices of Adverse Findings and
Section 305 notices and similar letters or  notices issued by the Food and  Drug
Administration  ("FDA") or any other governmental  entity that is concerned with
the safety, efficacy, reliability or manufacturing of the medical products  sold
by  Nellcor or its subsidiaries (hereafter  in this Section 4.21 "Medical Device
Regulatory Agency")  to Nellcor  or any  of  its subsidiaries  that are  in  the
aggregate  material to the conduct of Nellcor's business; (ii) all United States
Pharmacopoeia product problem reporting program complaints or reports,  MedWatch
FDA  forms 3500 and device experience  network complaints received by Nellcor or
any of its subsidiaries and all Medical  Device Reports filed by Nellcor or  any
of its subsidiaries, which complaints or reports
    

                                      A-15
<PAGE>
   
(A)  pertain to any  incident involving death  or serious injury,  and for which
incident there has been any of (x)  a notice or follow-up inquiry to Nellcor  by
the  FDA, (y) a litigation or arbitration claim or cause of action commenced, or
(z) a notice to any insurance carrier of Nellcor tendering the defense or giving
any notice of a  possible or actual  claim against Nellcor, and  (B) are in  the
aggregate  material  to the  conduct of  Nellcor's  business; (iii)  all product
recalls and  safety alerts  conducted by  or issued  to Nellcor  or any  of  its
subsidiaries  and any  requests from  the FDA  or any  Medical Device Regulatory
Agency requesting Nellcor or  any of its subsidiaries  to cease to  investigate,
test  or market any product, which recalls, safety alerts or requests are in the
aggregate material to the conduct of Nellcor's business; (iv) any civil  penalty
actions  begun by FDA or any Medical Device Regulatory Agency against Nellcor or
any of its subsidiaries and  known about by Nellcor  or any of its  subsidiaries
and   all  consent  decrees   issued  with  respect   to  Nellcor  or  Nellcor's
subsidiaries; and (v) any other written communications between Nellcor or any of
its subsidiaries, on the one hand, and the FDA or any Medical Device  Regulatory
Agency, on the other hand, which communications are in the aggregate material to
the  conduct of Nellcor's business.  Nellcor has delivered to  P-B copies of all
documents referred to in Section 4.21 of the Nellcor Disclosure Schedule as well
as copies of all complaints and  other information required to be maintained  by
Nellcor  pursuant to 21 CFR  Section 820, to the  extent that such complaints or
other information relate to events that  would in the aggregate have a  Material
Adverse Effect.
    

   
____(b)_Nellcor  (or, if applicable,  a subsidiary of  Nellcor) has obtained all
consents, approvals, certifications, authorizations and permits of, and has made
all filings with, or  notifications to, all  Medical Device Regulatory  Agencies
pursuant  to applicable requirements of all FDA laws, rules and regulations, and
all corresponding state and  foreign laws, rules  and regulations applicable  to
Nellcor  or any of its subsidiaries and  relating to its medical device business
or otherwise applicable to Nellcor's  or its subsidiaries' business, except  for
failures  to obtain or file any of the foregoing that would not in the aggregate
have a Material Adverse  Effect. All representations made  by Nellcor or any  of
its   subsidiaries   in   connection   with   any   such   consents,  approvals,
certifications, authorizations, permits, filings and notifications were true and
correct in all material respects at the time such representations and warranties
were made, and Nellcor's products,  and the products of Nellcor's  subsidiaries,
comply  with, and  perform in accordance  with the  specifications described in,
such representations,  except  for  instances of  noncompliance  or  failure  to
perform  that would not in the aggregate have a Material Adverse Effect. Nellcor
or Nellcor's subsidiaries are in compliance with all applicable FDA laws,  rules
and  regulations, and all corresponding applicable state and foreign laws, rules
and regulations  (including  Good  Manufacturing Practices  and  Medical  Device
Reporting   requirements)   relating   to  medical   device   manufacturers  and
distributors or  otherwise applicable  to Nellcor's  or Nellcor's  subsidiaries'
business,  except for instances of noncompliance that would not in the aggregate
have a Material Adverse Effect. Nellcor has no reason to believe that any of the
consents, approvals,  authorizations,  registrations,  certifications,  permits,
filings or notifications that it or any of its subsidiaries has received or made
to  operate  their  respective businesses  have  been  or are  being  revoked or
challenged, other  than such  revocations and  challenges as  would not  in  the
aggregate  have  a  Material  Adverse Effect.  There  are  no  investigations or
inquiries pending  or  threatened relating  to  the operation  of  Nellcor's  or
Nellcor's  subsidiaries' business  or Nellcor's compliance  with applicable laws
relating to its medical device business or otherwise applicable to Nellcor's  or
its subsidiaries' business, the outcome of which could reasonably be expected in
the aggregate to have a Material Adverse Effect.
    

   
____(c)_For  purposes of this  Section 4.21, the  term "Material Adverse Effect"
includes (i) any material injunction or criminal action or proceeding against or
involving Nellcor and (ii) any requirement that executive officers of Nellcor or
P-B be subjected  to a  consent decree or  become individually  involved in  any
proceeding in clause (i) above.
    

                                      A-16
<PAGE>
   
____4.22__REAL PROPERTY.__
    
   
____(a)_Section 4.22(a) of the Nellcor Disclosure Schedule lists all of the real
property  owned or currently used by Nellcor in the course of Nellcor's business
("Nellcor Real Property").  Section 4.22(a) of  the Nellcor Disclosure  Schedule
also  lists all material real property owned or used by Nellcor in the course of
Nellcor's business at any time since  December 31, 1984, other than the  Nellcor
Real Property.
    

   
____(b)_All  Nellcor  Real Property  is in  all  material respects  suitable and
adequate for the uses for  which it is currently  devoted. Nellcor has good  and
marketable  title in fee simple absolute  to the Nellcor Real Property indicated
on Section 4.22(a) of the Nellcor Disclosure Schedule to be owned by it, and  to
the  buildings,  structures  and  improvements thereon,  and  a  valid leasehold
interest in all other Nellcor Real Property, in each case free and clear of  all
Material Encumbrances (as defined below).
    

   
____(c)_To  Nellcor's knowledge,  all buildings, structures,  fixtures and other
improvements on the Nellcor  Real Property are in  good repair, free of  defects
(latent  or patent), and fit  for the uses to  which they are currently devoted,
except for deficiencies,  defects and  other conditions  that would  not in  the
aggregate  have  a Material  Adverse Effect.  To  Nellcor's knowledge,  all such
buildings, structures, fixtures  and improvements on  the Nellcor Real  Property
conform  to all applicable  laws, except for non-conformities  that would not in
the aggregate  have  a Material  Adverse  Effect. To  Nellcor's  knowledge,  the
buildings,  structures, fixtures and improvements on each parcel of Nellcor Real
Property lie  entirely within  the boundaries  of such  parcel of  Nellcor  Real
Property,  and no structures of any kind  encroach on the Nellcor Real Property,
except, in  each case,  for instances  of  encroachment that  would not  in  the
aggregate have a Material Adverse Effect.
    

   
____(d)_To  Nellcor's knowledge, none of the Nellcor Real Property is subject to
any Other  Agreement (as  defined  below) or  other  restriction of  any  nature
whatsoever  (recorded or unrecorded)  preventing or limiting  Nellcor's right to
use it,  except for  agreements or  other  restrictions that  would not  in  the
aggregate have a Material Adverse Effect.
    

   
____(e)_Except  for proceedings that would not  in the aggregate have a Material
Adverse Effect, to Nellcor's knowledge, no portion of the Nellcor Real  Property
or any building, structure, fixture or improvement thereon is the subject of, or
affected by, any condemnation, eminent domain or inverse condemnation proceeding
currently  instituted or pending, and  Nellcor has no knowledge  that any of the
foregoing are, or will be, the subject of, or affected by, any such proceeding.
    

   
____(f)_The Nellcor Real Property has direct and unobstructed access to adequate
electric, gas, water,  sewer and  telephone lines,  and public  streets, all  of
which  are adequate for the uses to which the Nellcor Real Property is currently
devoted, except  for obstructions  to access  and instances  of inadequacy  that
would not in the aggregate have a Material Adverse Effect.
    

   
____(g)_"Material  Encumbrance" means  any mortgage,  lien, pledge, encumbrance,
security interest,  deed of  trust,  option, encroachment,  reservation,  order,
decree,  judgment,  condition, restriction,  charge,  Other Agreement,  claim or
equity of  any  kind, except  for  (i) any  of  the foregoing  which  secures  a
liability which is accurately reflected in the financial statements of the party
whose  interest in property  is affected thereby;  (ii) liens for  taxes not yet
due; (iii)  easements or  other similar  rights which  do not  in the  aggregate
materially  interfere with the present use of the property affected thereby; and
(iv) other encumbrances  that do not  in the aggregate  have a Material  Adverse
Effect.
    

   
____(h)_"Other  Agreements" means  any agreement  or arrangement  between two or
more persons  (or  entities)  with  respect  to  their  relative  rights  and/or
obligations  or with  respect to  a thing  done or  to be  done (whether  or not
conditional, executory, express, implied, in writing or meeting the requirements
of contract),  including,  without  limitation,  contracts,  leases,  promissory
notes, covenants, easements, rights of way, commitments or understandings.
    

                                      A-17
<PAGE>
   
____4.23__RIGHTS  AGREEMENT.__Subject to there  being no material  change in the
representation and warranty contained in Section 5.24 (including Section 5.24 of
P-B Disclosure Schedule), neither the  execution and delivery of this  Agreement
nor  the  performance  by the  respective  parties hereto  of  their obligations
hereunder will give rise to a  "Shares Acquisition Date" or "Distribution  Date"
or  constitute  any person  or entity  an  "Acquiring Person,"  in each  case as
defined in the Nellcor Rights Agreement. As a result, Section 13 of the  Nellcor
Rights  Agreement is  not applicable  to the  transactions contemplated  by this
Agreement, including the Merger.
    

   
____4.24__SHARE OWNERSHIP.__As of the date hereof, to Nellcor's knowledge  there
are  no stockholders with beneficial ownership  (as defined in the Exchange Act)
of more than 5% of the Nellcor Common Stock.
    

   
____4.25__OPINION OF FINANCIAL  ADVISOR.__Nellcor has received  the opinions  of
Robertson, Stephens & Company, L.P. and Goldman, Sachs & Co. to the effect that,
as  of the  date hereof, the  Exchange Ratio is  fair to the  holders of Nellcor
Common Stock from a financial point of view.
    

   
                                   ARTICLE V
                     REPRESENTATIONS AND WARRANTIES OF P-B
    

   
____Except as set  forth in  the disclosure letter  delivered to  Nellcor at  or
prior  to  the  execution of  this  Agreement ("P-B  Disclosure  Schedule"), P-B
represents and warrants to Nellcor and Sub as follows:
    

   
____5.1__ORGANIZATION.__P-B is a  corporation duly  organized, validly  existing
and  in  good standing  under the  laws of  the  State of  Delaware and  has the
corporate power to carry on  its business as it is  now being conducted. P-B  is
duly  qualified as a foreign corporation to do business, and is in good standing
(to the extent the concept of good standing exists), in each jurisdiction  where
the  character of its properties owned or held  under lease or the nature of its
activities makes such qualification necessary, except where the failure to be so
qualified will  not  in the  aggregate  have  a Material  Adverse  Effect.  Each
subsidiary  of P-B is a corporation duly organized, validly existing and in good
standing (to the extent the concept of  good standing exists) under the laws  of
its  jurisdiction of incorporation  or organization, has  the corporate power to
carry on its business as  it is now being conducted  and is duly qualified as  a
foreign  corporation to do business, and is  in good standing (to the extent the
concept of good standing  exists), in each jurisdiction  where the character  of
its  properties owned or held under lease  or the nature of its activities makes
such qualification necessary, except where the failure to be so duly  organized,
validly  existing and in good standing, to have such corporate power or to be so
qualified will not  in the  aggregate have a  Material Adverse  Effect. P-B  has
delivered  to  Nellcor  or  its  counsel  complete  and  correct  copies  of its
Certificate of Incorporation and Bylaws.
    

   
____5.2__CAPITALIZATION.
    
   
____(a)_As of April 30,  1995, the authorized capital  stock of P-B consists  of
30,000,000  shares of P-B Common Stock. As  of April 30, 1995, 12,634,401 shares
of P-B Common Stock (including the associated rights under P-B Rights Agreement)
were issued and outstanding,  stock options to acquire  1,193,194 shares of  P-B
Common  Stock (the "P-B Stock Options")  were outstanding under all stock option
plans of P-B, and  524,070 additional shares of  P-B Common Stock were  reserved
for  issuance under P-B's stock  option plans. No changes  have occurred in such
capitalization since April 30, 1995 that, in the aggregate, would be material to
P-B, except for option exercises in  the ordinary course of business. Except  as
set  forth in Section 5.2 of the P-B  Disclosure Schedule, all of the issued and
outstanding  shares  of  P-B  Common  Stock  are  validly  issued,  fully  paid,
nonassessable  and  free  of  preemptive rights  or  similar  rights  created by
statute, the Certificate of Incorporation or By-laws of P-B or any agreement  to
which  P-B or any of its  subsidiaries is a party or by  which P-B or any of its
subsidiaries is bound. Since January 31, 1995, P-B has not issued any shares  of
its  capital stock, except upon the exercise  of P-B Stock Options and the grant
of Restricted Stock under  employee benefits plans and  issuances of P-B  Common
Stock pursuant to its 401(k) plan.
    

                                      A-18
<PAGE>
   
____(b)_Except as described in Section 5.2(b) of the P-B Disclosure Schedule and
as  set forth above and pursuant to  P-B employee benefit plans and as otherwise
provided for in this Agreement and the P-B Rights Agreement, there are not  now,
and  at the Effective Time there will not be, any shares of capital stock of P-B
issued or outstanding  or any options,  warrants, subscriptions, calls,  rights,
convertible  securities  or other  agreements or  commitments obligating  P-B to
issue, transfer or sell any shares of its capital stock. As of the date  hereof,
no Voting Debt of P-B was issued or outstanding, nor will there be any issued or
outstanding  at the Effective Time. Except as provided in this Agreement, and as
described in Section 5.2(b) of the P-B Disclosure Schedule, after the  Effective
Time,  P-B will have no obligation to issue,  transfer or sell any shares of its
capital stock pursuant to any employee benefit plan or otherwise. Except as  set
forth  in Section 5.2 of the P-B  Disclosure Schedule, all outstanding shares of
the capital stock  of P-B's subsidiaries  are validly issued,  fully paid,  non-
assessable  and owned by  P-B or one of  its subsidiaries free  and clear of any
liens, security interest, pledges, agreements, claims, charges, or  encumbrances
of  any nature  whatsoever. There  are no  voting trust  or other  agreements or
understandings to which P-B is a party with respect to the voting of the capital
stock of P-B or any of its  subsidiaries. Except as described in Section  5.2(b)
of  the P-B Disclosure Schedule, none of  P-B or its subsidiaries is required to
redeem, repurchase or otherwise acquire shares  of capital stock of P-B, or  any
of  its subsidiaries, respectively, as a result of the transactions contemplated
by this Agreement. Except as described  in Section 5.2(b) of the P-B  Disclosure
Schedule,  immediately  after  the  Effective Time,  there  will  be  no option,
warrant, call, right  or agreement obligating  P-B or any  subsidiary of P-B  to
issue,  deliver or sell, or cause to be issued, delivered or sold, any shares of
P-B Common Stock or any Voting Debt, or obligating P-B or any subsidiary of  P-B
to  grant,  extend, or  enter  into any  such  option, warrant,  call,  right or
agreement.
    

   
____5.3__AUTHORITY RELATIVE TO THIS AGREEMENT.__P-B  has the corporate power  to
enter  into  this Agreement  and  to carry  out  its obligations  hereunder. The
execution and delivery of this Agreement by  P-B and the consummation by P-B  of
the transactions contemplated hereby have been duly authorized by P-B's Board of
Directors  and, except  for the favorable  vote of  a majority of  the shares of
outstanding capital stock  of P-B entitled  to vote thereon  in accordance  with
Section  251(c) of the DGCL,  no other corporate proceedings  on the part of P-B
are necessary to approve this Agreement or the transactions contemplated hereby.
This Agreement  has been  duly and  validly executed  and delivered  by P-B  and
constitutes  a valid  and binding agreement  of P-B, enforceable  against P-B in
accordance with its terms.
    

   
____5.4__CONSENTS AND APPROVALS; NO VIOLATIONS.__Except as described in  Section
5.4  of the P-B  Disclosure Schedule, and except  for applicable requirements of
the HSR  Act,  the Securities  Act,  the Exchange  Act,  state or  foreign  laws
relating to takeovers, if applicable, state securities or blue sky laws, and the
filing  and recordation of a  Certificate of Merger as  required by the DGCL, no
filing with, and no permit, authorization, consent or approval of, any public or
governmental body or authority is necessary  for the consummation by P-B of  the
transactions  contemplated by this Agreement except where a failure to make such
filing or  to  obtain  such  permit,  registration,  authorization,  consent  or
approval  will not in  the aggregate have  a Material Adverse  Effect. Except as
described in Section 5.4 of the  P-B Disclosure Schedule, neither the  execution
and  delivery  of this  Agreement by  P-B, nor  the consummation  by P-B  of the
transactions contemplated  hereby,  nor  compliance  by  P-B  with  any  of  the
provisions  hereof,  will (a)  conflict  with or  result  in any  breach  of any
provisions of the Certificate of Incorporation or  By-Laws of P-B or any of  its
subsidiaries,  (b) result in  a violation or  breach of, or  constitute (with or
without due notice  or lapse of  time or both)  a default (or  give rise to  any
right  of termination, cancellation, acceleration or change in the award, grant,
vesting or determination) under, or give  rise to creation of any lien,  charge,
security interest or encumbrance upon any of the respective properties or assets
of  P-B  or any  of  its subsidiaries  under, any  of  the terms,  conditions or
provisions of  any note,  bond,  mortgage, indenture,  deed of  trust,  license,
contract,  lease, agreement,  arrangement or  other instrument  or obligation to
which P-B or any of its subsidiaries is a  party or by which any of them or  any
of their properties or assets may be bound or affected or (c) violate any order,
writ, injunction, decree, statute, rule or regulation of any court or government
authority  applicable to P-B, any of its subsidiaries or any of their properties
or assets, except in the case of clauses (b) and
    

                                      A-19
<PAGE>
   
(c) for violations, breaches, defaults (or rights of termination,  cancellation,
acceleration  or  change), liens,  charges,  security interests  or encumbrances
which would not in the aggregate have a Material Adverse Effect.
    

   
____5.5__REPORTS AND FINANCIAL STATEMENTS.__P-B has  filed a Schedule 14d-9  and
amendments thereto and all reports required to be filed with the SEC pursuant to
the  Exchange Act since December 31,  1984 including, without limitation, Annual
Reports on Form 10-K for the years ended January 31, 1994 and 1995 and Quarterly
Reports on Form 10-Q for  the quarters ended April 30,  1994, July 31, 1994  and
October  31,  1994  (the Schedule  14d-9  and  amendments thereto  and  all such
reports, collectively, the "P-B SEC  Reports"), and has previously furnished  or
made  available to Nellcor true and complete copies of all P-B SEC Reports filed
with respect  to  periods  beginning  after December  31,  1991  (including  any
exhibits thereto) and will promptly deliver to Nellcor any P-B SEC Reports filed
between the date hereof and the Effective Time. None of such P-B SEC Reports, as
of  their respective dates  (as amended through the  date hereof), contained or,
with respect to the P-B  SEC Reports filed after  the date hereof, will  contain
any  untrue statement of a material fact or  omitted or, with respect to the P-B
SEC Reports filed  after the date  hereof, will  omit to state  a material  fact
required  to be stated therein  or necessary to make  the statements therein, in
light of the circumstances under which  they were made, not misleading. Each  of
the balance sheets (including the related notes) included in the P-B SEC Reports
fairly  presents the consolidated financial position of P-B and its subsidiaries
as of the date thereof, and the other related statements (including the  related
notes) included therein fairly present the results of operations and the changes
in  cash flows of P-B and its  subsidiaries for the respective periods set forth
therein,  all  in  conformity  with  generally  accepted  accounting  principles
consistently  applied  during the  periods involved,  except as  otherwise noted
therein and subject, in the case of the unaudited interim financial  statements,
to  normal year end adjustments which would  not in the aggregate be material in
amount or effect.
    

   
____5.6__ABSENCE OF CERTAIN CHANGES OR  EVENTS.__Except as disclosed in the  P-B
SEC  Reports filed prior to the date  of this Agreement, since January 31, 1995,
neither P-B nor any of  its subsidiaries has: (a) taken  any of the actions  set
forth  in Sections  6.1(b), 6.1(c) or  6.1(e) hereof; (b)  incurred any material
liability, except in the ordinary course  of its business, consistent with  past
practices; (c) suffered any change, or any event involving a prospective change,
in  its business, assets, financial condition  or results of operation which has
had, or is reasonably likely to have, in the aggregate a Material Adverse Effect
(other than as  a result  of changes  or proposed  changes in  federal or  state
health care (including health care reimbursement) laws or regulations of general
applicability   or  interpretations  thereof,   changes  in  generally  accepted
accounting  principles  and  changes   that  could,  under  the   circumstances,
reasonably  have been anticipated in light of disclosures made in writing by P-B
to Nellcor prior to the execution of  this Agreement); or (d) subsequent to  the
date  hereof, except as permitted by  Section 6.1 hereof, conducted its business
and operations other than in the ordinary course of business and consistent with
past practices.
    

   
____5.7__INFORMATION  IN  REGISTRATION   STATEMENT  AND  PROXY   STATEMENT.__The
information  relating to P-B and  its subsidiaries to be  contained in the Proxy
Statement or the Registration Statement will not contain any untrue statement of
a material fact or omit to state any material fact required to be stated therein
or necessary  in  order  to  make  the  statements  therein,  in  light  of  the
circumstances under which they are made, not misleading.
    

   
____5.8__LITIGATION.__As  of the date of this  Agreement, except as disclosed in
the P-B SEC Reports filed prior to the date of this Agreement and except to  the
extent  that in the  aggregate they would  not reasonably be  expected to have a
Material  Adverse  Effect:   (i)  there   is  no  action,   suit,  judicial   or
administrative  proceeding, arbitration or investigation pending or, to the best
knowledge  of  P-B,  threatened  against  or   involving  P-B  or  any  of   its
subsidiaries,   or  any  of  their  properties  or  rights,  before  any  court,
arbitrator, or administrative or governmental  body; (ii) there is no  judgment,
decree,  injunction,  rule  or  order  of  any  court,  governmental department,
commission, agency, instrumentality
    

                                      A-20
<PAGE>
   
or arbitrator outstanding against P-B or any of its subsidiaries; and (iii)  P-B
and its subsidiaries are not in violation of any term of any judgments, decrees,
injunctions or orders outstanding against them.
    

   
____5.9__CONTRACTS.__
    
   
____(a)_Each   of  the   contracts,  instruments,   mortgages,  notes,  security
agreements, leases, agreements  or understandings, whether  written or oral,  to
which  P-B or any of its subsidiaries is  a party that relates to or affects the
assets or operations of P-B or any of its subsidiaries or to which P-B or any of
its subsidiaries  or their  respective  assets or  operations  may be  bound  or
subject  is a valid and  binding obligation of P-B and  in full force and effect
with respect to P-B or such subsidiary  and, to the best knowledge of P-B,  with
respect  to all other parties thereto, except for where the failure to be valid,
binding and in full force and effect would not in the aggregate have a  Material
Adverse  Effect. Except to the extent  that the consummation of the transactions
contemplated by this Agreement may require  the consent of third parties,  there
are no existing defaults by P-B or any of its subsidiaries thereunder or, to the
knowledge  of P-B, by any  other party thereto, which  defaults in the aggregate
would have a Material Adverse Effect; and no event of default has occurred,  and
no  event, condition or occurrence exists, that (whether with or without notice,
lapse of  time,  the  declaration  of default  or  other  similar  event)  would
constitute  a default by P-B  or any of its  subsidiaries thereunder, other than
defaults that would not in the aggregate have a Material Adverse Effect. Section
5.9(a) of  the P-B  Disclosure  Schedule lists  all  consents of  third  parties
required   for  the  consummation  of  the  transactions  contemplated  by  this
Agreement, other than  consents which  the failure to  obtain would  not in  the
aggregate have a Material Adverse Effect.
    

   
____(b)_Except  (A) as set forth in the  P-B SEC Reports (including the exhibits
thereto) filed prior to the date of this Agreement, (B) as set forth in  Section
5.9(b)  of the  P-B Disclosure  Schedule, and (C)  for this  Agreement and other
agreements that are not in the aggregate  material to P-B's business, as of  the
date of this Agreement neither P-B nor any of its subsidiaries is a party to any
oral   or  written   (i)  consulting   agreement,  (ii)   joint  venture,  (iii)
noncompetition or similar agreement that restricts P-B or its subsidiaries  from
engaging  in a line  of business, (iv)  agreement with any  executive officer or
other employee of P-B or any subsidiary the benefits of which are contingent, or
the terms of which are altered,  upon the occurrence of a transaction  involving
P-B  of the nature contemplated by this Agreement, or (v) agreement with respect
to any  executive  officer  of P-B  or  any  subsidiary providing  any  term  of
employment  or compensation guaranty.  Except as set forth  in Section 5.9(b) of
the P-B Disclosure Schedule, P-B has  no agreement or plan, including any  stock
option  plan, stock  appreciation rights  plan, restricted  stock plan  or stock
purchase plan, any of the benefits of which will be increased, or the vesting of
the benefits of  which will  be accelerated,  by the  occurrence of  any of  the
transactions  contemplated by this Agreement or the value of any of the benefits
of which will be calculated on the basis of any of the transactions contemplated
by this Agreement.
    

   
____(c)_Except as set forth  in Section 5.9(c) of  the P-B Disclosure  Schedule,
P-B has no agreements or arrangements to sell or otherwise dispose of, or lease,
acquire  or otherwise invest in, any property, lines of business or other assets
that are in the aggregate material to P-B's business, other than agreements  and
arrangements  for such sale, disposition,  lease, acquisition or investment that
are in the ordinary course of P-B's business.
    

   
____5.10__EMPLOYEE BENEFIT PLANS.
    
   
____(a)_Section 5.10  of the  P-B  Disclosure Schedule  sets  forth a  true  and
complete list of each material written or oral employee benefit plan (including,
without  limitation, any "employee  benefit plan" as defined  in Section 3(3) of
ERISA), policy  or  agreement  (including, without  limitation,  any  employment
agreement  or severance agreement) that is maintained (all of the foregoing, the
"P-B Plans"), or is  or was contributed to  by P-B or pursuant  to which P-B  is
still  potentially liable for payments,  benefits or claims. A  copy of each P-B
Plan as currently in effect and,  if applicable, the most recent Annual  Report,
Actuarial  Report or Valuation, Summary Plan  Description, Trust Agreement and a
Determination Letter issued by  the IRS for each  P-B Plan have heretofore  been
delivered to
    

                                      A-21
<PAGE>
   
Nellcor or its counsel. Neither P-B nor any ERISA Affiliate, which together with
P-B  would be deemed a  "single employer" within the  meaning of Section 4001 of
ERISA, has maintained or contributed to any plan subject to Title IV of ERISA or
Section 412  of the  Code  (including any  Multiemployer  Plan) during  the  six
calendar years preceding the date of this Agreement, other than the Restated P-B
Pension Plan.
    

   
____(b)_Each P-B Plan which is an "employee benefit plan", as defined in Section
3(3)  of ERISA,  complies by  its terms and  in operation  with the requirements
provided by any and  all statutes, orders or  governmental rules or  regulations
currently  in effect and  applicable to P-B  Plan, including but  not limited to
ERISA and the Code, except for instances of noncompliance that would not in  the
aggregate have a Material Adverse Effect.
    

   
____(c)_All  reports, forms  and other documents  required to be  filed with any
government entity with respect  to any P-B  Plan (including without  limitation,
summary  plan descriptions,  Forms 5500  and summary  annual reports)  have been
timely filed and are accurate, except for instances of noncompliance that  would
not in the aggregate have a Material Adverse Effect.
    

   
____(d)_Each  P-B Plan intended to qualify under  Section 401(a) of the Code has
been determined by the Internal Revenue  Service to so qualify after January  1,
1985,  and each  trust maintained  pursuant thereto  has been  determined by the
Internal Revenue Service  to be exempt  from taxation under  Section 501 of  the
Code.  Except as set  forth in Section  5.10(d) of the  P-B Disclosure Schedule,
nothing has occurred since the date of the Internal Revenue Service's  favorable
determination  letter that could  adversely affect the  qualification of the P-B
Plan and its  related trust, except  such adverse  effects as would  not in  the
aggregate  constitute a Material Adverse Effect. P-B and each ERISA Affiliate of
P-B have timely and properly applied for a written determination by the Internal
Revenue Service on the qualification of each such P-B Plan and its related trust
under Section 401(a) of the Code, as amended  by the Tax Reform Act of 1986  and
subsequent  legislation enacted through the date  hereof, and Section 501 of the
Code.
    

   
____(e)_Except as set forth in Section  5.10(e) of the P-B Disclosure  Schedule,
all  contributions or other amounts payable by P-B or its subsidiaries as of the
Effective Time with respect to each P-B Plan and in respect of current or  prior
plan  years have been  or will be (prior  to the Effective  Time) either paid or
accrued on the Financial Statements of P-B in accordance with past practice  and
the recommended contribution in any actuarial report.
    

   
____(f)_No  P-B Plan  provides benefits,  including without  limitation death or
medical benefits (whether  or not insured),  with respect to  current or  former
employees  for periods extending beyond their retirement or other termination of
service (other than (i) continuation  group health coverage pursuant to  Section
4980B  of  the  Code,  (ii)  death benefits  or  retirement  benefits  under any
"employee pension plan," as that term is defined in Section 3(2) of ERISA, (iii)
deferred compensation benefits  with respect  to which  there is  an accrual  of
liability  on the books of  P-B or its ERISA  Affiliates, (iv) benefits the full
cost of  which is  borne  by the  current  or former  employee  (or his  or  her
beneficiary),  (v) benefits set  forth in Section 5.10(f)  of the P-B Disclosure
Schedule, or (vi)  benefits which  in the aggregate  are not  material to  P-B's
business).
    

   
____(g)_All  insurance  premiums  (including  premiums  to  the  Pension Benefit
Guaranty  Corporation)  have  been  paid   in  full,  subject  only  to   normal
retrospective  adjustments in the ordinary course,  with regard to P-B Plans for
plan years ending on  or before the  date hereof, except  for instances of  non-
payment that would not in the aggregate have a Material Adverse Effect.
    

   
____(h)_As  of the date hereof, no P-B Plan subject to Title IV of ERISA, and no
employee benefit plan  maintained by an  ERISA Affiliate of  P-B and subject  to
Title IV of ERISA, has benefit liabilities (as defined in Section 4001(a)(16) of
ERISA)  exceeding the assets  of such plan  or has been  completely or partially
terminated.
    

                                      A-22
<PAGE>
   
____(i)_Except as set forth  in Section 5.10(i) of  the P-B Disclosure  Schedule
and  except for prohibited transactions, reportable events and actions or claims
as would not in the  aggregate have a Material  Adverse Effect, with respect  to
each P-B Plan:
    

   
    ____(1)_no  prohibited transactions  (as defined  in Section  406 or  407 of
    ERISA or  Section 4975  of the  Code) have  occurred for  which a  statutory
    exemption is not available;
    

   
    ____(2)_no  reportable  event  (as defined  in  Section 4043  of  ERISA) has
    occurred as to which a notice would be required to be filed with the Pension
    Benefit Guaranty Corporation;
    

   
    ____(3)_no action or claims (other than routine claims for benefits made  in
    the  ordinary course  of Plan  administration for  which Plan administrative
    review procedures have not been exhausted) are pending or, to the  knowledge
    of  P-B, threatened  or imminent  against or with  respect to  P-B Plan, any
    employer who is participating (or who  has participated) in any Plan or  any
    fiduciary  (as defined in Section  3(21) of ERISA), of  the P-B Plan, except
    for actions  or claims  that would  not  in the  aggregate have  a  Material
    Adverse Effect; and
    

   
    ____(4)_neither  P-B nor any fiduciary has  any knowledge of any facts which
    could give rise to any such action or claim.
    

   
____(j)__Neither P-B nor  any ERISA  Affiliate of P-B  has any  liability or  is
threatened with any liability (whether joint or several) (i) for the termination
of any single employer plan under Sections 4062 or 4064 of ERISA or any multiple
employer  plan under  Section 4063  of ERISA,  (ii) for  any lien  imposed under
Section 302(f) of ERISA or  Section 412(n) of the  Code, (iii) for any  interest
payments  required under Section 302(e) of ERISA  or Section 412(m) of the Code,
(iv) for any excise tax  imposed by Sections 4971, 4975,  4976, 4977 or 4979  of
the  Code, (v) for any minimum funding contributions under Section 302(c)(11) of
ERISA or Section 412(c)(11)  of the Code,  (vi) to a fine  under Section 502  of
ERISA, or (vii) for any transaction within the meaning of Section 4069 of ERISA,
except  in each case for such liabilities that would not in the aggregate have a
Material Adverse Effect.
    

   
____(k)_P-B has  not  incurred any  withdrawal  liability with  respect  to  any
Multiemployer  Plan within the meaning of Sections  4201 and 4204 of ERISA which
would in the aggregate have a Material Adverse Effect, and no liabilities  exist
with respect to withdrawals from any Multiemployer Plans which could subject P-B
to  any controlled group liability under Section 4001(b) of ERISA which would in
the aggregate have a Material Adverse Effect.
    

   
____(l)_All of  the P-B  Plans, to  the extent  applicable, are  in  substantial
compliance  with the continuation of  group health coverage provisions contained
in Section 4980B of the Code and  Sections 601 through 608 of ERISA, except  for
such instances of noncompliance which would not in the aggregate have a Material
Adverse Effect.
    

   
____5.11__TAX  MATTERS.__P-B makes the  following representations and warranties
with respect to tax matters.
    
   
____(a)__DEFINITIONS.__For  purposes  of  this   Section  5.11,  the   following
definitions shall apply:
    

   
    ____(1)_The  term "P-B Group" shall mean, individually and collectively, (i)
    P-B and (ii) any  individual, trust, corporation,  partnership or any  other
    entity  as to which P-B  is liable for Taxes  incurred by such individual or
    entity either as a transferee,  or pursuant to Treasury Regulations  Section
    1.1502-6, or pursuant to any other provision of federal, territorial, state,
    local or foreign law or regulations.
    

   
    ____(2)_The   term  "Taxes"  shall  mean  all  taxes,  however  denominated,
    including any interest, penalties or other additions to tax that may  become
    payable  in  respect thereof,  imposed by  any federal,  territorial, state,
    local or foreign government  or any agency or  political subdivision of  any
    such  government, which taxes shall include, without limiting the generality
    of the foregoing, all  income or profits taxes  (including, but not  limited
    to,  federal  income taxes  and state  income  taxes), payroll  and employee
    withholding  taxes,   unemployment   insurance,   social   security   taxes,
    

                                      A-23
<PAGE>
   
    sales  and use taxes, ad valorem taxes, excise taxes, franchise taxes, gross
    receipts taxes, business license taxes, occupation taxes, real and  personal
    property  taxes, stamp taxes, transfer taxes, workers' compensation, Pension
    Benefit Guaranty Corporation  premiums and other  governmental charges,  and
    other  obligations  of  the  same or  of  a  similar nature  to  any  of the
    foregoing, which the P-B Group is required to pay, withhold or collect.
    

   
    ____(3)_The term "Returns" shall  mean all reports, estimates,  declarations
    of  estimated  tax,  information  statements  and  returns  relating  to, or
    required to be filed  in connection with,  any Taxes, including  information
    returns  or reports with respect to backup withholding and other payments to
    third parties.
    

   
____(b)__RETURNS FILED AND  TAXES PAID.__Except for  instances of  noncompliance
that  would not in the aggregate have a Material Adverse Effect, (i) all Returns
required to be filed by or on behalf of members of the P-B Group have been  duly
filed  on a timely basis  and such Returns are  true, complete and correct, (ii)
all Taxes shown to be payable on  the Returns or on subsequent assessments  with
respect  thereto have been  paid in full on  a timely basis,  and (iii) no other
Taxes are payable by the P-B Group  with respect to items or periods covered  by
such  Returns (whether or  not shown on  or reportable on  such Returns) or with
respect to any period prior to the date of this Agreement. Except for  instances
of noncompliance that would not in the aggregate have a Material Adverse Effect,
each  member of the P-B  Group has withheld and paid  over all Taxes required to
have been withheld and  paid over, and complied  with all information  reporting
and  backup withholding requirements, including  maintenance of required records
with respect thereto, in connection with amounts paid or owing to any  employee,
creditor,  independent contractor, or  other third party.  Except for liens that
would not in the aggregate have a Material Adverse Effect, there are no liens on
any of the assets of  any member of the P-B  Group with respect to Taxes,  other
than  liens for Taxes not yet due and payable  or for Taxes that a member of the
P-B Group is contesting  in good faith through  appropriate proceedings and  for
which appropriate reserves have been established.
    

   
____(c)__TAX  RESERVES.__The amount of P-B's liability  for unpaid Taxes for all
periods ending on or before the date of this Agreement does not in the aggregate
exceed the  amount  of  the  current liability  accruals  for  Taxes  (excluding
reserves  for deferred Taxes) reflected on the consolidated balance sheet of P-B
included in the P-B  SEC Report for  the quarter ending closest  to the date  of
this  Agreement, and  the amount  of P-B's  liability for  unpaid Taxes  for all
periods ending on or before the Effective Time shall not in the aggregate exceed
the amount of the current liability  accruals for Taxes (excluding reserves  for
deferred  Taxes), as  such accruals  are reflected  on the  consolidated balance
sheet of P-B included in  the P-B SEC Report for  the quarter ending closest  to
the  Effective Time, except (as to all  matters covered in this Section 5.11(c))
for any excess that does not in the aggregate have a Material Adverse Effect.
    

   
____(d)__CONSOLIDATED RETURNS FURNISHED.__Nellcor has been furnished by P-B true
and complete copies of (i) income tax audit reports, statements of deficiencies,
closing or other agreements received by P-B Group or on behalf of the P-B  Group
relating  to federal income taxes,  and (ii) all federal  income tax returns for
the P-B Group, in  each case for  all periods ending on  and after December  31,
1991.  P-B has never  been a member  of an affiliated  group filing consolidated
returns other than a group of which P-B was the common parent.
    

   
____(e)__TAX DEFICIENCIES;  AUDITS;  STATUTES OF  LIMITATIONS.__No  deficiencies
exist  or  have  been  asserted  (either in  writing  or  verbally,  formally or
informally) or are  expected to be  asserted with  respect to Taxes  of the  P-B
Group  that would cause P-B's reserves for  taxes to be understated in an amount
material to P-B. Except  as disclosed in Section  5.11(e) of the P-B  Disclosure
Schedule,  no federal income  tax returns of  the P-B Group  are currently under
audit, and no waiver  or extension of  the statute of  limitations is in  effect
with respect to any federal income tax returns.
    

   
____(f)__TAX  SHARING AGREEMENTS.__P-B is not (nor has  it ever been) a party to
any tax sharing agreement.
    

                                      A-24
<PAGE>
   
____(g)__TAX ELECTIONS  AND  SPECIAL TAX  STATUS.__Nellcor  is not  required  to
withhold tax on the acquisition of the stock of P-B by reason of Section 1445 of
the  Code. No member  of P-B Group  is a "consenting  corporation" under Section
341(f) of the Code.
    

   
____(h)__SECTION 6038A COMPLIANCE.__Except for  instances of noncompliance  that
would  not in the aggregate  have a Material Adverse  Effect and any maintenance
agreements that are not in the aggregate material to P-B: (i) P-B has filed  all
reports and has created and/or retained all records required under Section 6038A
of  the Code  with respect  to its  ownership by  and transactions  with related
parties; (ii) each  related foreign  person required to  maintain records  under
Section  6038A with respect to transactions  between P-B and the related foreign
person has maintained such records; (iii) all documents that are required to  be
created  and/or  preserved  by  the  related  foreign  person  with  respect  to
transactions with P-B  are either  maintained in the  United States,  or P-B  is
exempt from the record maintenance requirements of Section 6038A with respect to
such transactions under Treasury Regulation section 1.6038A-1; (iv) P-B is not a
party to any record maintenance agreement with the Internal Revenue Service with
respect  to Section 6038A; and (v) each  related foreign person that has engaged
in transactions with P-B has authorized P-B  to act as its limited agent  solely
for  purposes of Sections 7602,  7603, and 7604 of the  Code with respect to any
request by the Internal Revenue Service to examine records or produce  testimony
related to any transaction with P-B, and each such authorization remains in full
force and effect.
    

   
____5.12__COMPLIANCE  WITH APPLICABLE LAW.__Except  as disclosed in  the P-B SEC
Reports filed  prior  to  the date  of  this  Agreement, P-B  and  each  of  its
subsidiaries  holds  all licenses,  franchises, permits,  variances, exemptions,
orders, approvals and  authorizations necessary  for the lawful  conduct of  its
business  under  and  pursuant to,  and  the business  of  each of  P-B  and its
subsidiaries is  not being  conducted  in violation  of,  any provision  of  any
federal,  state,  local or  foreign statute,  law, ordinance,  rule, regulation,
judgment, decree,  order, concession,  grant, franchise,  permit or  license  or
other  governmental authorization  or approval applicable  to P-B or  any of its
subsidiaries, except to the extent that  the failure to hold any such  licenses,
franchises, permits, variances, exemptions, orders, approvals or authorizations,
or  the  existence of  any such  violation, would  not in  the aggregate  have a
Material Adverse Effect.
    

   
____5.13__SUBSIDIARIES.__Exhibit 21 to P-B's most  recent Form 10-K included  in
the  P-B SEC Reports  lists all the subsidiaries  of P-B as of  the date of this
Agreement  and  indicates  for  each  such  subsidiary  as  of  such  date   the
jurisdiction of incorporation or organization.
    

   
____5.14__SECTION 203 OF THE DGCL NOT APPLICABLE.__The Board of Directors of P-B
has approved the transactions contemplated by this Agreement pursuant to Section
203(a)(1)  of the DGCL  such that (assuming the  accuracy of the representations
contained in Section 4.16) the remaining  provisions of Section 203 are  thereby
made  inapplicable  to  the Merger  and  the transactions  contemplated  by this
Agreement.
    

   
____5.15__LABOR AND EMPLOYMENT MATTERS.
    
   
____(a)_Except for such matters that would not in the aggregate have a  Material
Adverse  Effect, (i) P-B  and its subsidiaries  are and have  been in compliance
with all applicable laws respecting  employment and employment practices,  terms
and conditions of employment and wages and hours, including, without limitation,
IRCA,   WARN,  and   such  laws  respecting   employment  discrimination,  equal
opportunity, affirmative action, worker's compensation, occupational safety  and
health  requirements and unemployment insurance and related matters, and are not
engaged in  and  have  not  engaged  in  any  unfair  labor  practice;  (ii)  no
investigation  or review  by or  before any  governmental entity  concerning any
violations of any such applicable laws is  pending or, to the knowledge of  P-B,
threatened, nor has any such investigation occurred during the last seven years,
and  no  governmental  entity has  provided  any notice  to  P-B or  any  of its
subsidiaries asserting an  intention to  conduct any  such investigation;  (iii)
there  is no labor strike, dispute, slowdown or stoppage actually pending or, to
the knowledge of P-B, threatened against P-B or any of its subsidiaries; (iv) no
union representation
    

                                      A-25
<PAGE>
   
question or union organizational activity exists respecting the employees of P-B
or  any of its subsidiaries; and (v) neither P-B nor any of its subsidiaries has
experienced any work stoppage or other labor difficulty.
    

   
____No collective bargaining agreement exists which is binding on P-B or any  of
its subsidiaries.
    

   
____(b)_Except for benefits provided under agreements and plans described in the
P-B  SEC Reports or  in Section 5.15(b)  of the P-B  Disclosure Schedule, in the
event of termination of the employment of any officers, directors, employees  or
agents  of P-B or any of its subsidiaries, neither P-B, any of its subsidiaries,
Nellcor, Sub, the Surviving Corporation, nor any other subsidiaries of  Nellcor,
will  pursuant  to any  agreement or  by reason  of anything  done prior  to the
Effective Time  by P-B  or any  of its  subsidiaries be  liable to  any of  said
officers,  directors, employees or  agents for so-called  "severance pay" or any
other   similar   payments   or   benefits,   including,   without   limitation,
post-employment healthcare (other than pursuant to COBRA) or insurance benefits.
    

   
____5.16__OWNERSHIP  OF SHARES OF NELLCOR COMMON  STOCK.__As of the date hereof,
neither P-B nor, to its knowledge, any of its affiliates or associates (as  such
terms  are defined under  the Exchange Act), (a)  beneficially owns, directly or
indirectly, or (b) is party to  any agreement, arrangement or understanding  for
the  purpose of acquiring, holding, voting or disposing of, in each case, shares
of Nellcor Common Stock, except  for (i) shares of  Nellcor Common Stock in  the
aggregate  representing less than 1% of the outstanding shares of Nellcor Common
Stock and  (ii) the  "standstill" provisions  of the  Confidentiality  Agreement
relating to the acquisition of Nellcor Common Stock.
    

   
____5.17__INSURANCE.__As  of the date  hereof, P-B and  each of its subsidiaries
are insured by insurers reasonably believed by P-B to be of recognized financial
responsibility against  such  losses  and  risks and  in  such  amounts  as  are
customary  in the businesses in which they are engaged. All material policies of
insurance and fidelity or surety bonds  insuring P-B or any of its  subsidiaries
or their respective businesses, assets, employees, officers and directors are in
full force and effect. Except as described in Section 5.17 of the P-B Disclosure
Schedule,  as of the date hereof, there are  no material claims by P-B or any of
its subsidiaries under any such policy  or instrument as to which any  insurance
company is denying liability or defending under a reservation of rights clause.
    

   
____5.18__CONTRACTS   WITH   PHYSICIANS,   HOSPITALS,  HMOS   AND   THIRD  PARTY
PROVIDERS.__P-B has made available to representatives  of Nellcor a list of  all
outstanding  contracts, partnerships,  joint ventures and  other arrangements or
understandings (written or oral)  that are material to  P-B's business and  that
are  between (a) P-B or any of its subsidiaries and (b) any physician, hospital,
HMO, other managed care organization, or other third-party provider relating  to
the  sale or supply of  medical devices, the provision  of medical or consulting
services, treatments or patient referrals or any other similar activities.
    

   
____5.19__ENVIRONMENTAL PROTECTION.
    
   
____(a)_None of P-B, P-B's subsidiaries, or, to the best of P-B's knowledge, any
P-B Property (as defined in sub-section (d)  below) is or has been in  violation
of  any Environmental Law, except for violations that would not in the aggregate
have a Material Adverse Effect.
    

   
____(b)_Neither P-B nor  any of its  subsidiaries has reported  any, or has  had
knowledge  of any circumstances  giving rise to  any reporting requirement under
applicable Environmental Laws  as to any,  spills or releases  of any  Hazardous
Material that would in the aggregate have a Material Adverse Effect, nor has P-B
or  any  of its  subsidiaries  received any  notices  of spills  or  releases of
Hazardous Materials that would in the aggregate have a Material Adverse Effect.
    

   
____(c)_There is  no  proceeding  or  investigation  pending  or,  to  the  best
knowledge  of P-B,  threatened by any  governmental entity or  other person with
respect to  the  presence of  Hazardous  Material  on P-B's  Properties  or  the
migration  thereof from or to other property  that would in the aggregate have a
    

                                      A-26
<PAGE>
   
Material Adverse Effect. Neither P-B nor  any of its subsidiaries has ever  been
required by any governmental entity to treat, clean up, or otherwise dispose of,
remove  or neutralize any  Hazardous Material from  or on any  P-B Property that
would in the aggregate have a Material Adverse Effect.
    

   
____(d)_Neither P-B, any  current or  former subsidiary  of P-B,  nor any  other
person  has engaged in any activity that might reasonably be expected to involve
the generation, use, manufacture, treatment, transportation, storage in tanks or
otherwise, or disposal of Hazardous Material on or from any property that P-B or
any of its current or former subsidiaries  now owns or leases or has  previously
owned  or  leased or  in  which P-B  or  any such  subsidiary  now holds  or has
previously held any security interest, mortgage, or other lien or interest ("P-B
Property")  which  generation,  use,  manufacture,  treatment,   transportation,
storage  or disposal would in the aggregate  have a Material Adverse Effect, and
no (i) presence, release, threatened  release, discharge, spillage or  migration
of  Hazardous Material, (ii) condition that has  resulted or could result in any
use, ownership  or  transfer  restriction,  or  (iii)  condition  of  actual  or
potential  nuisance has occurred on or from  such P-B Property, and no condition
exists  that  could  give  rise  to  any  suit,  claim,  action,  proceeding  or
investigation  by  any person  or governmental  entity against  P-B, any  of its
subsidiaries or any  other person  or such  P-B Property as  a result  of or  in
connection  with (a) any of the foregoing  events, (b) any failure to obtain any
required permits or approvals of any  governmental entity, (c) the violation  of
any  terms  or  conditions  of  such permits,  or  (d)  any  other  violation of
Environmental Laws; other  than (as  to all  of the  foregoing matters)  events,
failures,  violations  or conditions  that  would not  in  the aggregate  have a
Material Adverse Effect.
    

   
____(e)_To the best of P-B's knowledge, there are no substances or conditions in
or on  P-B Property  which may  support claims  or causes  of action  under  any
applicable  Environmental Law,  which claims  or causes  of action  would in the
aggregate have a Material Adverse Effect.
    

   
____(f)_For purposes of this  Section 5.19, the  term "Material Adverse  Effect"
includes (i) any material injunction or criminal action or proceeding against or
involving P-B and (ii) any requirement that executive officers of Nellcor or P-B
be  subjected  to  a  consent  decree or  become  individually  involved  in any
proceeding in clause (i) above.
    

   
____5.20__INTELLECTUAL PROPERTY RIGHTS.
    
   
____(a)_Section 5.20(a) of the  P-B Disclosure Schedule  sets forth an  accurate
and complete list of all (i) patents, applications for patents, registrations of
trademarks (including service marks) and applications therefor and registrations
of  copyrights and applications therefor  that are owned by  P-B or any of P-B's
subsidiaries and that  are in  the aggregate  material to  P-B's business;  (ii)
other  Intellectual Property Rights that are  owned by P-B or P-B's subsidiaries
and that are in the aggregate material  to the conduct of P-B's business;  (iii)
unexpired  licenses  relating to  P-B Intellectual  Property Rights  (as defined
below) that have been granted to or by P-B or any of P-B's subsidiaries and that
are in the aggregate material to the  conduct of P-B's business; and (iv)  other
agreements  relating to Intellectual  Property Rights that  are in the aggregate
material to the conduct of P-B's business.
    

   
____(b)_To P-B's knowledge, P-B and P-B's subsidiaries collectively own and have
the right to use, and  to license others to  use, all P-B Intellectual  Property
Rights that are in the aggregate material to the conduct of P-B's business. Such
ownership and right to use, and to license others to use, are free and clear of,
and  without liability under, all liens  and security interests of third parties
that would in the aggregate be  material to P-B's business. To P-B's  knowledge,
such  ownership and  right to use,  and to license  others to use,  are free and
clear of, and without  liability under, all claims  and rights of third  parties
that,  if determined to  be legally protectable,  could in the  aggregate have a
Material Adverse Effect.
    

   
____(c)_P-B has taken reasonable steps sufficient to safeguard and maintain  the
secrecy  and confidentiality of, or P-B's  proprietary rights in, the unpatented
know-how, technology,  proprietary processes,  formulae, and  other  information
that  is in the aggregate material to  the conduct of P-B's business, including,
without limitation, the know-how,  technology, proprietary processes,  formulae,
    

                                      A-27
<PAGE>
   
and  other information  listed as  trade secrets in  Section 5.20(c)  of the P-B
Disclosure Schedule. Without limitation of  the generality of the foregoing,  to
P-B's  knowledge, P-B and  P-B's subsidiaries have  obtained confidentiality and
inventions assignment agreements from substantially  all P-B's past and  present
employees and independent contractors involved in the creation or development of
P-B  Intellectual  Property  Rights  (including,  without  limitation,  from all
employees and contractors who are inventors, authors, creators or developers  of
P-B  Intellectual Property  Rights) that  are in  the aggregate  material to the
conduct of P-B's business.
    

   
____(d)_Except for  licenses listed  in Section  5.20(d) of  the P-B  Disclosure
Schedule  as royalty-bearing, there  are no royalties,  honoraria, fees or other
payments payable by  P-B or  P-B subsidiaries  to any  person by  reason of  the
ownership,  use,  license,  sale or  disposition  of any  of  P-B's Intellectual
Property Rights,  which  Intellectual  Property  Rights  are  in  the  aggregate
material to the conduct of P-B's business.
    

   
____(e)_Neither  P-B  nor any  of P-B's  subsidiaries (i)  is infringing  in the
conduct of P-B's business  the right or  claimed right of  any other party  with
respect  to  any Intellectual  Property  Rights, or  (ii)  has knowledge  of any
alleged or claimed infringement  by any product  or process manufactured,  used,
sold  or under development by or for P-B or P-B's subsidiaries in the conduct of
P-B's business that, if proven, would  in the aggregate have a Material  Adverse
Effect.
    

   
____(f)_To  P-B's  knowledge,  no  independent  contractors  who  have performed
services related to P-B's  business have any right,  title or interest in  P-B's
Intellectual Property Rights that in the aggregate can be reasonably expected to
have a Material Adverse Effect.
    

   
____(g)_The  execution, delivery and  performance of this  Agreement by P-B, and
the consummation  by  P-B of  the  transactions contemplated  hereby,  will  not
breach,  violate  or conflict  with any  agreement governing  P-B's Intellectual
Property Rights  that are  in the  aggregate material  to the  conduct of  P-B's
business,  will not cause the forfeiture or  termination or give rise to a right
of forfeiture or termination of P-B's Intellectual Property Right or in any  way
impair the right of P-B to use, sell, license or dispose of, or bring any action
for the infringement of, P-B's Intellectual Property Rights or portion thereof.
    

   
____(h)_For  purposes of this Section 5.20,  "use," with respect to Intellectual
Property Rights,  includes  make, reproduce,  display  or perform  (publicly  or
otherwise),  prepare derivative works  based on, sell,  distribute, disclose and
otherwise exploit such Intellectual  Property Rights and products  incorporating
or subject to such Intellectual Property Rights.
    

   
____(i)_As  used in this Agreement, the  term "P-B Intellectual Property Rights"
means all  Intellectual Property  Rights that  are part  of the  conduct of  the
business of P-B.
    

   
____(j)__For  purposes of  this Section 5.20,  the term "material"  when used in
reference to rights or agreements, shall  mean rights or agreements the loss  or
impairment  of which  in the  aggregate could be  reasonably expected  to have a
Material Adverse Effect.
    

   
____5.21__FDA AND RELATED MATTERS.
    
   
____(a)_Section 5.21 of the  P-B Disclosure Schedule sets  forth a complete  and
accurate  list, referencing  relevant records and  documents, for  the last five
years, of (i) all Regulatory or Warning Letters, Notices of Adverse Findings and
Section 305 notices  and similar letters  or notices  issued by the  FDA or  any
other   governmental  entity  that  is  concerned  with  the  safety,  efficacy,
reliability or  manufacturing  of  the  medical products  sold  by  P-B  or  its
subsidiaries (hereafter in this Section 5.21 "Medical Device Regulatory Agency")
to  P-B or  any of its  subsidiaries that are  in the aggregate  material to the
conduct of P-B's business; (ii) all United States Pharmacopoeia product  problem
reporting  program complaints  or reports,  MedWatch FDA  forms 3500  and device
experience network complaints received by P-B or any of its subsidiaries and all
Medical Device Reports filed by P-B or any of its subsidiaries, which complaints
or reports (A) pertain  to any incident involving  death or serious injury,  and
for  which incident there has  been any of (x) a  notice or follow-up inquiry to
P-B by  the FDA,  (y)  a litigation  or arbitration  claim  or cause  of  action
commenced,    or   (z)   a   notice   to    any   insurance   carrier   of   P-B
    

                                      A-28
<PAGE>
   
tendering the defense or giving any notice of a possible or actual claim against
P-B, and (B) are  in the aggregate  material to the  conduct of P-B's  business;
(iii) all product recalls and safety alerts conducted by or issued to P-B or any
of  its  subsidiaries  and any  requests  from  the FDA  or  any  Medical Device
Regulatory Agency  requesting  P-B  or  any of  its  subsidiaries  to  cease  to
investigate,  test  or  market  any product,  which  recalls,  safety  alerts or
requests are in the  aggregate material to the  conduct of P-B's business;  (iv)
any  civil penalty actions begun by FDA  or any Medical Device Regulatory Agency
against P-B or  any of its  subsidiaries and known  about by P-B  or any of  its
subsidiaries  and  all  consent decrees  issued  with  respect to  P-B  or P-B's
subsidiaries; and (v) any other written communications between P-B or any of its
subsidiaries, on the  one hand,  and the FDA  or any  Medical Device  Regulatory
Agency, on the other hand, which communications are in the aggregate material to
the  conduct  of P-B's  business. P-B  has  delivered to  Nellcor copies  of all
documents referred to in Section 5.21 of the P-B Disclosure Schedule as well  as
copies  of all complaints and other information required to be maintained by P-B
pursuant to 21  CFR Section 820,  to the  extent that such  complaints or  other
information relate to events that would in the aggregate have a Material Adverse
Effect.
    

   
____(b)_P-B  (or, if applicable, a subsidiary of P-B) has obtained all consents,
approvals, certifications,  authorizations  and permits  of,  and has  made  all
filings  with,  or  notifications  to, all  Medical  Device  Regulatory Agencies
pursuant to applicable requirements of all FDA laws, rules and regulations,  and
all  corresponding state and  foreign laws, rules  and regulations applicable to
P-B or any of its  subsidiaries and relating to  its medical device business  or
otherwise applicable to P-B's or its subsidiaries' business, except for failures
to  obtain or file any of  the foregoing that would not  in the aggregate have a
Material Adverse  Effect.  All  representations  made  by  P-B  or  any  of  its
subsidiaries  in connection  with any such  consents, approvals, certifications,
authorizations, permits, filings and notifications were true and correct in  all
material respects at the time such representations and warranties were made, and
P-B's products, and the products of P-B's subsidiaries, comply with, and perform
in accordance with the specifications described in, such representations, except
for  instances of  noncompliance or  failure to  perform that  would not  in the
aggregate have  a Material  Adverse Effect.  P-B or  P-B's subsidiaries  are  in
compliance  with  all  applicable  FDA  laws,  rules  and  regulations,  and all
corresponding  applicable  state  and   foreign  laws,  rules  and   regulations
(including   Good   Manufacturing   Practices  and   Medical   Device  Reporting
requirements) relating  to  medical  device manufacturers  and  distributors  or
otherwise  applicable  to  P-B's  or P-B's  subsidiaries'  business,  except for
instances of  noncompliance that  would not  in the  aggregate have  a  Material
Adverse  Effect.  P-B  has  no  reason to  believe  that  any  of  the consents,
approvals, authorizations,  registrations, certifications,  permits, filings  or
notifications that it or any of its subsidiaries has received or made to operate
their  respective businesses have been or are being revoked or challenged, other
than such  revocations and  challenges as  would  not in  the aggregate  have  a
Material  Adverse Effect.  There are no  investigations or  inquiries pending or
threatened relating to the operation of P-B's or P-B's subsidiaries' business or
P-B's compliance with applicable laws relating to its medical device business or
otherwise applicable  to P-B's  or its  subsidiaries' business,  the outcome  of
which  could reasonably be expected in the  aggregate to have a Material Adverse
Effect.
    

   
____(c)_For purposes of this  Section 5.21, the  term "Material Adverse  Effect"
includes (i) any material injunction or criminal action or proceeding against or
involving P-B and (ii) any requirement that executive officers of P-B or Nellcor
be  added as  a named  individual party to  the consent  decree to  which P-B is
presently subject.
    

   
____5.22__REAL PROPERTY.
    
   
____(a)_Section 5.22(a) of  the P-B Disclosure  Schedule lists all  of the  real
property  owned or currently  used by P-B  in the course  of P-B's business (the
"P-B Real Property"). Section 5.22(a) of the P-B Disclosure Schedule also  lists
all  material  real property  owned  or used  by P-B's  in  the course  of P-B's
business at any time since December 31, 1984, other than P-B Real Property.
    

   
____(b)_All P-B Real Property is in all material respects suitable and  adequate
for  the uses  for which it  is currently  devoted. P-B has  good and marketable
title in fee simple absolute to P-B Real Property
    

                                      A-29
<PAGE>
   
indicated on Section 5.22(a) of the P-B  Disclosure Schedule to be owned by  it,
and to the buildings, structures and improvements thereon, and a valid leasehold
interest  in all  other P-B Real  Property, in each  case free and  clear of all
Material Encumbrances (as defined in Section 4.22(g)).
    

   
____(c)_To P-B's  knowledge,  all  buildings,  structures,  fixtures  and  other
improvements on P-B Real Property are in good repair, free of defects (latent or
patent),  and fit for the  uses to which they  are currently devoted, except for
deficiencies, defects and other conditions that would not in the aggregate  have
a  Material Adverse Effect. To P-B's  knowledge, all such buildings, structures,
fixtures and improvements on P-B's Real Property conform to all applicable laws,
except for non-conformities  that would  not in  the aggregate  have a  Material
Adverse  Effect.  To P-B's  knowledge, the  buildings, structures,  fixtures and
improvements on  each  parcel of  P-B  Real  Property lie  entirely  within  the
boundaries  of such parcel of  P-B Real Property, and  no structures of any kind
encroach  on  P-B  Real  Property,  except,  in  each  case,  for  instances  of
encroachment that would not in the aggregate have a Material Adverse Effect.
    

   
____(d)_To  P-B's knowledge,  none of  the P-B Real  Property is  subject to any
Other Agreement  or other  restriction  of any  nature whatsoever  (recorded  or
unrecorded)  preventing or limiting P-B's right to use it, except for agreements
or other restrictions that  would not in the  aggregate have a Material  Adverse
Effect.
    

   
____(e)_Except  for proceedings that would not  in the aggregate have a Material
Adverse Effect, to P-B's knowledge, no portion  of the P-B Real Property or  any
building,  structure,  fixture  or improvement  thereon  is the  subject  of, or
affected by, any condemnation, eminent domain or inverse condemnation proceeding
currently instituted  or pending,  and P-B  has  no knowledge  that any  of  the
foregoing are, or will be, the subject of, or affected by, any such proceeding.
    

   
____(f)_The  P-B Real  Property has direct  and unobstructed  access to adequate
electric, gas, water,  sewer and  telephone lines,  and public  streets, all  of
which  are adequate  for the uses  to which  the P-B Real  Property is currently
devoted, except  for obstructions  to access  and instances  of inadequacy  that
would not in the aggregate have a Material Adverse Effect.
    

   
____5.23__RIGHTS   AGREEMENT.__Neither  the  execution   and  delivery  of  this
Agreement nor  the  performance  by  the  respective  parties  hereto  of  their
obligations   hereunder  will  give  rise  to  a  "Stock  Acquisition  Date"  or
"Distribution Date" or constitute Nellcor or Sub an "Acquiring Person," in  each
case  as defined in that certain Rights  Agreement dated May 2, 1989 between P-B
and UMB Bank, N.A., as amended (the "P-B Rights Agreement"). P-B shall take  any
further  action  necessary prior  to the  Effective Time  to cause  the dilutive
provisions of the P-B Rights Agreement to be inapplicable to the Merger, without
any payment to holders of rights issued under the P-B Rights Agreement.
    

   
____5.24__SHARE OWNERSHIP.__As of the date hereof, to P-B's knowledge there  are
no  stockholders with beneficial  ownership (as defined in  the Exchange Act) of
more than 5% of P-B Common Stock.
    

   
____5.25__OPINION OF FINANCIAL ADVISORS.__P-B has received the opinion of  Smith
Barney  Inc. to the  effect that, as of  the date hereof,  the Exchange Ratio is
fair to the holders of P-B Common Stock from a financial point of view.
    

   
                                   ARTICLE VI
                     CONDUCT OF BUSINESS PENDING THE MERGER
    

   
____6.1__CONDUCT OF BUSINESS BY P-B AND NELLCOR PENDING THE MERGER.__During  the
period  from the date of this Agreement and continuing until the Effective Time,
except as set forth in  Section 6.1 of each of  the P-B Disclosure Schedule  and
the Nellcor Disclosure Schedule:
    

   
____(a)_the  respective businesses of  P-B and its  subsidiaries and Nellcor and
its subsidiaries shall  be conducted only  in the ordinary  and usual course  of
business and consistent with past practices;
    

                                      A-30
<PAGE>
   
____(b)_neither  P-B nor Nellcor or their respective subsidiaries shall (i) sell
or pledge  or agree  to sell  or pledge  any stock  owned by  it in  any of  its
subsidiaries;  (ii) amend its Certificate of  Incorporation or By-Laws; or (iii)
split, combine or  reclassify any  shares of  its outstanding  capital stock  or
declare,  set aside or pay  any dividend or other  distribution payable in cash,
stock or property  in respect of  its capital stock,  or directly or  indirectly
redeem,  purchase or otherwise acquire any shares  of its capital stock or other
securities or shares  of the capital  stock or  other securities of  any of  its
subsidiaries,  other than (i)  in connection with  the use of  shares of capital
stock to  pay the  exercise price  or tax  withholdings in  connection with  its
stock-based  employee  benefit  plans  in the  ordinary  course  of  business in
accordance with  past practice,  and (ii)  P-B's $0.03  per share  regular  cash
dividend declared in May, 1995.
    

   
____(c)  neither  P-B or  any  of its  subsidiaries nor  Nellcor  or any  of its
subsidiaries shall (i) authorize for issuance, issue, sell, pledge, dispose  of,
encumber,  deliver or  agree or  commit to issue,  sell, pledge,  or deliver any
additional shares  of, or  rights of  any kind  to acquire  any shares  of,  its
capital  stock of any class or exchangeable into shares of stock of any class or
any Voting Debt (whether through the issuance or granting of options,  warrants,
commitments,  subscriptions,  rights  to  purchase  or  otherwise),  except  for
unissued shares of Nellcor Common Stock or P-B Common Stock, as the case may be,
reserved for  issuance  upon the  exercise  of  the stock  options  or  warrants
described  (A)  in  the case  of  Nellcor,  in the  Nellcor  Disclosure Schedule
pursuant to Nellcor's employee and  director stock plans or  (B) in the case  of
P-B, in the P-B Disclosure Schedule pursuant to P-B's employee stock plans; (ii)
acquire,  dispose of, transfer, lease, license, mortgage, pledge or encumber any
material fixed or other  assets, other than in  the ordinary course of  business
and  consistent with past practices; (iii)  incur, assume or prepay any material
indebtedness, liability or obligation or any other material liabilities or issue
any debt  securities,  other  than  in  the  ordinary  course  of  business  and
consistent  with past  practices; (iv)  assume, guarantee,  endorse or otherwise
become liable or responsible (whether  directly, contingently or otherwise)  for
the  obligations of  any other  person (other than  a subsidiary)  in a material
amount, other than in the ordinary  course of business and consistent with  past
practices; (v) make any material loans, advances or capital contributions to, or
investments in, any other person (other than to subsidiaries), other than in the
ordinary  course of  business and consistent  with past practices;  (vi) fail to
maintain adequate insurance consistent with past practices for their  businesses
and  properties;  or (vii)  enter into  any  contract, agreement,  commitment or
arrangement with respect to any of the foregoing;
    

   
____(d)_each of P-B and  Nellcor shall use its  best efforts to preserve  intact
the  business organization  of P-B  and its subsidiaries,  on the  one hand, and
Nellcor and its subsidiaries, on the other hand, to keep available the  services
of its and its subsidiaries' present officers and key employees, and to preserve
the   goodwill  of  those   having  business  relationships   with  it  and  its
subsidiaries; PROVIDED, HOWEVER, that no breach of this representation shall  be
deemed  to have occurred if a failure  to comply with this Section 6.1(d) occurs
as a result of any matter arising  out of the transactions contemplated by  this
Agreement  or any  acquisition proposals  made to P-B  or Nellcor  or the public
announcement thereof;
    

   
____(e)_neither P-B, Nellcor nor any of their respective subsidiaries shall  (i)
knowingly  take, or  allow to  be taken, any  action which  would jeopardize the
treatment of the  Merger as a  pooling of interests  for accounting purposes  or
(ii)  knowingly take, or allow to be taken or fail to take any action, which act
or omission would  jeopardize qualification  of the Merger  as a  reorganization
within the meaning of Section 368(a) of the Code; and
    

   
____(f)_each  of  P-B  and  Nellcor  shall,  and  shall  cause  their respective
subsidiaries to, use all reasonable  efforts not to take  any action and not  to
omit  to take any action (and  not to agree in writing  or otherwise to take any
such action or make any  such omission) the effect  of which action or  omission
would  be  to  make  any  representation  or  warranty  of  P-B  or  Nellcor, as
applicable, herein untrue or incorrect in any material respect.
    

                                      A-31
<PAGE>
   
____6.2__CONDUCT OF BUSINESS OF  SUB.__During the period from  the date of  this
Agreement  to the Effective Time, Sub shall  not engage in any activities of any
nature except as provided in or contemplated by this Agreement.
    

   
____6.3__COMPENSATION PLANS.__During the period from the date of this  Agreement
and  continuing until the Effective  Time, each of P-B  and Nellcor agrees as to
itself and its subsidiaries that it will not, without the prior written  consent
of  the other party hereto (except as  required by applicable law or pursuant to
existing contractual  arrangements or  solely to  the extent  necessary to  make
compensation  increases in the ordinary course  of business consistent with past
practices or make  available existing  benefit arrangements to  new or  promoted
employees  in the ordinary course of business in accordance with past practice):
(a) enter into, adopt  or amend any bonus,  profit sharing, compensation,  stock
option,  pension,  retirement, deferred  compensation, employment,  severance or
other employee benefit plan, agreement,  trust, plan, fund or other  arrangement
between  P-B  or  Nellcor, as  applicable,  and  one or  more  of  its officers,
directors or  employees, in  each case  so as  to materially  increase  benefits
thereunder  (collectively, "Compensation Plans"), (b)  grant or become obligated
to grant  any increase  in the  compensation or  fringe benefits  of  directors,
officers  or employees (including any such increase pursuant to any Compensation
Plan) or any increase in  the compensation payable or  to become payable to  any
officer, except, with respect to employees other than officers, for increases in
compensation  in the ordinary course of  business consistent with past practice,
or enter  into  any  contract,  commitment  or arrangement  to  do  any  of  the
foregoing,  except for  normal increases  and non-stock  benefit changes  in the
ordinary course of business consistent with past practice, (c) institute any new
employee benefit, welfare program or Compensation  Plan, (d) make any change  in
any  Compensation Plan or other employee welfare or benefit arrangement or enter
into any employment or  similar agreement or arrangement  with any employee,  or
(e)  enter  into or  renew any  contract,  agreement, commitment  or arrangement
providing for the payment to any  director, officer or employee of  compensation
or benefits contingent, or the terms of which are materially altered in favor of
such  individual, upon the occurrence of any of the transactions contemplated by
this Agreement.
    

   
____6.4__CURRENT INFORMATION.__From the date of this Agreement to the  Effective
Time,  each  of  P-B  and Nellcor  will  cause  one or  more  of  its designated
representatives to  confer  on a  regular  and  frequent basis  (not  less  than
semi-monthly) with representatives of the other and to report the general status
of  its ongoing operations and to deliver to the other (not less than quarterly)
unaudited consolidated  balance sheets  and related  consolidated statements  of
income, changes in stockholders equity and changes in financial position for the
period  since the last such report. Each of P-B and Nellcor will promptly notify
the  other  of  any  material  change  in  the  normal  course  of  its  or  its
subsidiaries' business or in its or its subsidiaries' properties.
    

   
____6.5__LETTERS   OF  P-B'S  AND  NELLCOR'S  ACCOUNTANTS.__P-B  shall  use  all
reasonable efforts to cause to be delivered to Nellcor a letter of Ernst & Young
LLP ("Ernst &  Young"), P-B's independent  auditors, and Nellcor  shall use  all
reasonable efforts to cause to be delivered to P-B a letter of Price Waterhouse,
LLP ("Price Waterhouse"), Nellcor's independent auditors, each such letter dated
a  date  within two  business days  before  the date  on which  the Registration
Statement shall become effective and addressed to Nellcor or P-B, as applicable,
in form and substance  reasonably satisfactory to such  recipient, and in  scope
and  substance  consistent with  applicable  professional standards  for letters
delivered by  independent public  accountants  in connection  with  registration
statements  similar to the  Registration Statement. Each of  P-B and Nellcor, if
requested by the other, shall use reasonable efforts to cause to be delivered to
the other an update, dated the Closing Date, of the letter of their  independent
auditors described in the preceding sentence.
    

   
____6.6__LEGAL  CONDITIONS TO MERGER.__Each of P-B  and Nellcor shall, and shall
cause its subsidiaries to, use all reasonable  efforts (a) to take, or cause  to
be  taken, all actions necessary to  comply promptly with all legal requirements
which may be  imposed on  such party  or its  subsidiaries with  respect to  the
Merger  and the consummation of the transactions contemplated by this Agreement,
subject to the  appropriate vote or  consent of stockholders  and (b) to  obtain
(and  to cooperate with  the other party to  obtain) any consent, authorization,
order   or   approval    of,   or   any    exemption   by,   any    governmental
    

                                      A-32
<PAGE>
   
entity  or  any other  public or  private third  party which  is required  to be
obtained or made by such party or any of its subsidiaries in connection with the
Merger and the transactions contemplated  by this Agreement; PROVIDED,  HOWEVER,
that a party shall not be obligated to take any action pursuant to the foregoing
if  the  taking of  such  action or  such compliance  or  the obtaining  of such
consent, authorization,  order, approval  or exemption  would, in  such  party's
reasonable  opinion,  (i)  be  materially  burdensome  to  such  party  and  its
subsidiaries taken as a whole or impact in such a materially adverse manner  the
economic or business benefits of the transactions contemplated by this Agreement
as to render inadvisable the consummation of the Merger or (ii) to result in the
imposition  of a  condition or  restriction on  such party  or on  the Surviving
Corporation of the type referred to in  Section 8.1(e). Each of P-B and  Nellcor
will  promptly cooperate with and furnish information to the other in connection
with any such burden suffered  by, or requirement imposed  upon, any of them  or
any of their subsidiaries in connection with the foregoing.
    

   
____6.7__AFFILIATES.__Not  later than ten days prior  to the date of the mailing
of the joint Proxy Statement referred to in Section 7.4, each of P-B and Nellcor
shall deliver to the other a letter identifying all persons who are "affiliates"
of P-B or Nellcor, as applicable, for purposes of Rule 145 under the  Securities
Act.  Each of  P-B and Nellcor  shall use  all reasonable efforts  to cause each
person named in the letter delivered by it  to deliver to the other party on  or
before  such mailing date  a written "affiliates"  agreement, in customary form,
restricting the disposition by such person of the shares of Nellcor Common Stock
to be  received by  such  person in  the  Merger. Certificates  surrendered  for
exchange  by any person constituting an "affiliate" of P-B within the meaning of
Rule 145 under the Securities Act shall  not be exchanged by the Exchange  Agent
for  shares of Nellcor  Common Stock pursuant  to Section 3.2  until the parties
have received such agreement described in the preceding sentence.
    

   
____6.8__ADVICE OF CHANGES;  GOVERNMENT FILINGS.__Each party  shall confer on  a
regular  and frequent  basis with the  other, report on  operational matters and
shall promptly advise  the other both  orally and  in writing of  any change  or
event  having, or which,  insofar as can  reasonably be foreseen,  could have, a
Material Adverse  Effect on  such party  or which  would cause  or constitute  a
material  breach of any of the  representations, warranties or covenants of such
party contained herein. Nellcor  and P-B shall file  all reports required to  be
filed  by each of them with  the SEC between the date  of this Agreement and the
Effective Time and shall deliver to the  other party copies of all such  reports
promptly  after  the  same  are filed.  Except  where  prohibited  by applicable
statutes and regulations, and  subject to Section 7.1  hereof, each party  shall
promptly  provide the other  (or its counsel)  with copies of  all other filings
made by such  party with any  state or federal  government entity in  connection
with this Agreement or the transactions contemplated hereby.
    

   
____6.9__ACCOUNTING  METHODS.__Except as otherwise contemplated by Section 7.13,
neither Nellcor nor P-B shall change its methods of accounting in effect at July
3, 1994 or  January 31,  1995, respectively, except  as required  by changes  in
generally  accepted  accounting  principles  as  concurred  in  by  such party's
independent auditors. Neither Nellcor nor P-B will change its fiscal year.
    

   
                                  ARTICLE VII
                             ADDITIONAL AGREEMENTS
    

   
____7.1__ACCESS AND INFORMATION.
    
   
____(a)_P-B and Nellcor and their  respective subsidiaries shall each afford  to
the  other and  to the other's  financial advisors,  legal counsel, accountants,
consultants and  other  representatives  access  during  normal  business  hours
throughout  the period from the date hereof to  the Effective Time to all of its
books,  records,  properties,  facilities,  personnel  commitments  and  records
(including  but not limited to Tax Returns)  and, during such period, each shall
furnish  promptly  to  the  other  all  information  concerning  its   business,
properties  and  personnel  as  such  other  party  may  reasonably  request. No
investigation pursuant to this Section  7.1 shall affect any representations  or
warranties  made herein or  the conditions to the  obligations of the respective
parties to consummate the Merger.
    

                                      A-33
<PAGE>
   
____(b)_All information furnished by P-B to  either Nellcor or Sub or  furnished
by  either or both of Nellcor and Sub to P-B pursuant hereto shall be treated as
the sole property of the party furnishing the information until consummation  of
the Merger contemplated hereby. The parties will hold any such information which
is nonpublic in confidence to the extent required by, and in accordance with the
Confidentiality  Agreement, and such Confidentiality Agreement shall survive the
termination of this Agreement.
    

   
____7.2__NO SOLICITATION  OF  TRANSACTIONS.__From  the  date  hereof  until  the
earlier  of termination of this Agreement or consummation of the Merger, neither
P-B on the one hand, nor Nellcor on the other hand, nor any of their  respective
subsidiaries  will,  directly  or  indirectly,  whether  through  any  director,
officer, employee, financial advisor, legal counsel, accountant, other agent  or
representative  (as used  in this Section  7.2, "affiliates")  or otherwise, (A)
initiate, solicit  or encourage,  or take  any other  action to  facilitate  any
inquiries  or the making of  any proposal with respect to,  or (B) except to the
extent required  in  the  exercise of  the  fiduciary  duties of  the  Board  of
Directors of P-B or Nellcor, as the case may be, under applicable law as advised
by  independent counsel  in connection with  an unsolicited  proposal, engage or
participate in  negotiations concerning,  provide any  nonpublic information  or
data  to, or have any discussions with, any  person other than a party hereto or
their affiliates relating to, any (i) acquisition, (ii) tender offer  (including
a self-tender offer), (iii) exchange offer, (iv) merger, (v) consolidation, (vi)
acquisition  of  beneficial  ownership  of  (or  the  right  to  vote securities
representing) 10% or more of the total voting power of such entity or any of its
subsidiaries, (vii) dissolution, (viii)  business combination, (ix) purchase  of
all  or any significant portion of the assets  or any division of (or any equity
interest in) such entity or any subsidiary, or (x) any similar transaction other
than the Merger (such proposals,  announcements, or transactions being  referred
to  as "Acquisition Proposals"). Each  of P-B and Nellcor  will notify the other
orally (within one business day) and in writing (as promptly as practicable)  if
any  such Acquisition  Proposals (including the  identity of  the persons making
such proposals and, subject to the fiduciary duties of the Board of Directors of
P-B or Nellcor, the  terms of such  proposals) are received  and furnish to  the
other party hereto a copy of any written proposal.
    

   
____7.3__REGISTRATION  STATEMENT.__As promptly  as practicable,  Nellcor and P-B
shall cooperate and prepare and Nellcor shall file with the SEC the Registration
Statement and use reasonable efforts to have the Registration Statement declared
effective. Nellcor shall also use reasonable efforts to take any action required
to be taken  under state  securities or  blue sky  laws in  connection with  the
issuance  of  the shares  of  Nellcor Common  Stock  pursuant hereto.  P-B shall
furnish Nellcor  with all  information concerning  P-B and  the holders  of  its
capital stock and shall take such other action as Nellcor may reasonably request
in connection with such Registration Statement and issuance of shares of Nellcor
Common Stock.
    

   
____7.4__PROXY  STATEMENTS;  STOCKHOLDER  APPROVALS.__Nellcor  and  P-B,  acting
through  their  respective  Boards  of  Directors,  shall,  in  accordance  with
applicable law and their Certificates of Incorporation and By-Laws:
    

   
____(a)_promptly  and duly  call, give  notice of, convene  and hold  as soon as
practicable following the  date upon  which the  Registration Statement  becomes
effective  a meeting of their respective  stockholders for the purpose of voting
to approve and adopt this Agreement and shall use their respective best efforts,
except to the extent  required in the  exercise of the  fiduciary duties of  the
Board  of Directors of P-B or Nellcor, as  the case may be, under applicable law
as advised by independent counsel, to obtain such stockholders approval;
    

   
____(b)_except to the extent required in the exercise of the fiduciary duties of
the Board of Directors of P-B or  Nellcor, as the case may be, under  applicable
law  as advised by independent counsel,  recommend approval and adoption of this
Agreement by the stockholders of  Nellcor, on the one hand,  and of P-B, on  the
other  hand, and include  in the Proxy Statement  such recommendations, and take
all lawful action to solicit such approvals; and
    

                                      A-34
<PAGE>
   
____(c)_as promptly as practicable, prepare and file with the SEC a  preliminary
joint  Proxy Statement and,  after consultation with each  other, respond to any
comments of the SEC  with respect to the  preliminary Proxy Statement and  cause
the definitive Proxy Statement to be mailed to their respective stockholders. At
the  stockholders' meeting of  P-B, Nellcor shall  vote or cause  to be voted in
favor of approval and adoption of this Agreement all shares of P-B Common  Stock
which  it beneficially owns at such time. Whenever any event occurs which should
be set forth  in an  amendment or  a supplement to  the Proxy  Statement or  any
filing  required to be  made with the  SEC, each party  will promptly inform the
other and will cooperate in filing  with the SEC and/or mailing to  stockholders
such  amendment  or  supplement. The  Proxy  Statement, and  all  amendments and
supplements thereto,  shall  comply with  applicable  law  and be  in  form  and
substance satisfactory to Nellcor and P-B.
    

   
____7.5__NASDAQ  NATIONAL  MARKET.__Nellcor  shall  notify  the  Nasdaq National
Market of  the listing  of  the shares  of Nellcor  Common  Stock to  be  issued
pursuant to the Merger.
    

   
____7.6__ANTITRUST LAWS.__As promptly as practicable, P-B, Nellcor and Sub shall
make all filings and submissions under the HSR Act as may be reasonably required
to  be made in connection with  this Agreement and the transactions contemplated
hereby. Subject to Section 7.1 hereof, P-B will furnish to Nellcor and Sub,  and
Nellcor  and Sub  will furnish  to P-B, such  information and  assistance as the
other may reasonably  request in  connection with  the preparation  of any  such
filings  or submissions. Subject to Section 7.1 hereof, P-B will provide Nellcor
and  Sub,  and  Nellcor   and  Sub  will  provide   P-B,  with  copies  of   all
correspondence,  filings  or  communications  (or  memoranda  setting  forth the
substance thereof) between such party or any of its representatives, on the  one
hand,  and any governmental  agency or authority or  members of their respective
staffs, on the other hand, with  respect to this Agreement and the  transactions
contemplated  hereby, except  to the  extent that Nellcor  or P-B  is advised by
independent counsel that the provision of such information would be  inadvisable
under applicable antitrust laws.
    

   
____7.7__CERTAIN EMPLOYEE BENEFIT PLANS MATTERS.
    
   
____(a)_Nellcor  confirms to P-B that it  is Nellcor's present intent to provide
after the Effective  Time to continuing  employees of P-B  and its  subsidiaries
employee benefit programs that in the aggregate are generally not less favorable
to  such employees than those being provided  to Nellcor's employees on the date
of this  Agreement, except  as otherwise  provided IN  SCHEDULE 7.7(A).  To  the
extent  the Nellcor employee benefit programs  provide medical or dental welfare
benefits after the Closing Date, Nellcor shall cause all pre-existing  condition
exclusions  and actively  at work requirements  to be waived,  and Nellcor shall
provide that any expenses incurred on or before the Closing Date shall be  taken
into  account  under  the  Nellcor employee  benefit  programs  for  purposes of
satisfying the  applicable  deductible, coinsurance  and  maximum  out-of-pocket
provisions for such employees and their covered dependents.
    

   
____(b)_P-B  hereby confirms to  Nellcor that (i) all  P-B Stock Options granted
under the 1988 Stock Benefit  Plan that are not fully  vested as of the date  of
this  Agreement provide for acceleration  of vesting or exercisability effective
30 days prior to the Merger and  all restricted stock awards granted under  such
plan  provide for acceleration  of vesting upon  the Merger, (ii)  all P-B Stock
Options under the 1988 Stock Benefit Plan expire upon consummation of the Merger
and (iii) all P-B Stock Options under the 1979 Employee Stock Benefit Plan shall
carry over and become options to acquire Nellcor Common Stock.
    

   
____(c)_P-B confirms that it  has amended its Change  of Control Severance  Plan
effective  on or prior to  the date hereof so that  (i) none of the transactions
contemplated by this Agreement will constitute a "Change of Control" as  defined
therein,  and (ii)  effective immediately prior  to consummation  of the Merger,
such Change of Control  Severance Plan shall without  any further action on  the
part  of P-B automatically terminate and be  of no further force and effect. P-B
agrees that it  shall not  rescind or  alter such  amendment or  take any  other
action to nullify its effect without the prior written consent of Nellcor.
    

                                      A-35
<PAGE>
   
____(d)_Except  as set forth in  SCHEDULE 7.7(D), P-B shall  take no action from
and after  the date  hereof to  deposit  into any  trust (including  any  "rabbi
trust") amounts in respect of any employee benefit obligations.
    

   
____(e)_P-B  confirms that it has  amended its Management Incentive Compensation
Plan A and  Plan B  for Fiscal  Year 1996  in accordance  with Section  II(e)(6)
thereof  to provide that no further benefits shall be payable thereunder subject
to the consummation of the Merger and that such plans shall without any  further
action on the part of P-B automatically terminate and be of no further force and
effect  from and after the Merger. P-B agrees that it shall not rescind or alter
such amendment or take any other action to nullify its effect without the  prior
written  consent  of  Nellcor.  In  lieu  of  the  benefits  payable  under such
Management Incentive  Compensation Plan  A  and Plan  B  for Fiscal  Year  1996,
Nellcor  shall  cause P-B  to adopt  immediately after  the consummation  of the
Merger, a Merger Incentive Compensation Plan (which shall be effective from  and
after  the consummation of the Merger) for  the benefit of employees of P-B that
previously participated in such Management  Incentive Compensation Plans on  the
terms and conditions as set forth in SCHEDULE 7.7(E).
    

   
____(f)_From  and after the  Effective Time, neither Nellcor  nor P-B shall take
any action  to amend  or  modify P-B's  Directors Post-Retirement  Income  Plan,
except  that such plan shall not be  available to new directors of P-B appointed
by Nellcor from and after  the Merger. P-B shall  continue to make all  payments
required  to be made under such plan to  each former director of P-B entitled to
benefits thereunder (regardless of whether such director subsequently serves  as
a  director of Nellcor). Neither P-B nor Nellcor shall fund any rabbi trust with
respect to such plan, provided that Nellcor will guarantee the payment by P-B of
P-B's obligations under such plan.
    

   
____(g)_P-B confirms that it will amend its Supplemental Retirement Benefit Plan
and its Pension Benefit Make Up Plan effective on or prior to the Effective Time
in the manner specified in SCHEDULE 7.7(G).
    

   
____(h)_Nellcor shall cause P-B to  adopt immediately after consummation of  the
Merger,  a Retention Compensation Plan (which  shall be effective from and after
the consummation  of  the  Merger)  for the  benefit  of  certain  senior  level
employees of P-B on the terms and conditions as set forth in SCHEDULE 7.7(H).
    

   
____7.8__STOCK OPTIONS AND WARRANTS.
    
   
____(a)_As  of  the Effective  Time,  each of  the  P-B Stock  Options  which is
outstanding as of the date hereof and  has not expired as of the Effective  Time
shall  be assumed by Nellcor  and converted into an  option (or a new substitute
option shall be  granted) to  purchase the number  of shares  of Nellcor  Common
Stock  (rounded up to the nearest whole share)  equal to the number of shares of
P-B Common Stock subject to such option multiplied by the Exchange Ratio, at  an
exercise  price per share of  Nellcor Common Stock (rounded  down to the nearest
penny) equal to the former  exercise price per share  of P-B Common Stock  under
such  option immediately  prior to  the Effective  Time divided  by the Exchange
Ratio; PROVIDED, HOWEVER,  that in the  case of  any P-B Stock  Option to  which
Section 421 of the Code applies by reason of its qualification under Section 422
of  the Code, the conversion formula shall  be adjusted, if necessary, to comply
with Section 424(a)  of the  Code. Except as  provided above,  the converted  or
substituted  P-B Stock Options shall be subject to the same terms and conditions
(including,  without   limitation,  expiration   date,  vesting   and   exercise
provisions)  as were  applicable to P-B  Stock Options immediately  prior to the
Effective Time.
    

   
____(b)_As of the  Effective Time,  Nellcor shall  grant an  option intended  to
qualify  as  an  incentive  stock  option  under  Section  422  of  the  Code in
substitution for each incentive stock option (within the meaning of Section  422
of  the Code) which (i)  was issued by P-B under  P-B's 1988 Stock Benefit Plan,
(ii) had its vesting and exercisability accelerated under the terms of the  1988
Stock  Benefit Plan as a result of  the Merger, and (iii) expired unexercised as
of the  Effective  Time.  As  of  the Effective  Time,  Nellcor  shall  grant  a
non-qualified  stock option in substitution for each  P-B Stock Option that is a
non-qualified stock option which  (i) was issued by  P-B under P-B's 1988  Stock
Benefit Plan, (ii) had its
    

                                      A-36
<PAGE>
   
vesting and exercisability accelerated under the terms of the 1988 Stock Benefit
Plan  as  a  result of  the  Merger, and  (iii)  expired unexercised  as  of the
Effective Time. The  number of  shares of Nellcor  Common Stock  subject to  the
substituted  options under each of the preceding two sentences, and the exercise
price per share of such Nellcor Common Stock, shall be based upon the number  of
shares  of P-B Common Stock and the exercise price per share of P-B Common Stock
under the terms  of the  expired option,  in each  case as  provided in  Section
7.8(a). To the extent that any P-B Stock Options under P-B's 1979 Employee Stock
Benefit Plan would terminate as of the Effective Time as a result of the Merger,
Nellcor  shall make appropriate arrangements to substitute equivalent options to
acquire Nellcor Common Stock on the  same basis as provided herein with  respect
to  options under P-B's 1988  Stock Benefit Plan. Subject  to the foregoing, all
substituted options under this Section  7.8(b) to purchase Nellcor Common  Stock
shall  be subject  to the same  terms and  conditions as were  applicable to the
expired P-B Stock Options  for which they are  substituted immediately prior  to
the  Effective Time, except that the  acceleration of vesting and exercisability
as a result of the Merger shall not be given effect.
    

   
____(c)_Nellcor agrees that within fifteen (15) days after the Effective Time it
will cause to be filed one or more registration statements on Form S-8 under the
Securities Act, or amendments  to its existing  registration statements on  Form
S-8  or amendments to such other registration statements as may be available, in
order to register the shares of  Nellcor Common Stock issuable upon exercise  of
the  aforesaid converted  P-B Stock  Options, and at  or prior  to the Effective
Time, Nellcor shall take all corporate action necessary to reserve for  issuance
a sufficient number of shares of Nellcor Common Stock for delivery upon exercise
of the options substituted pursuant to this Section 7.8. The consummation of the
Merger  shall not be treated as a  termination of employment for purposes of the
Option Plans.
    

   
____7.9__DIRECTOR AND OFFICER INDEMNIFICATION, ETC.
    
   
____(a)_Nellcor  and  the  Surviving  Corporation  each  agrees  that  for  acts
occurring  prior  to  the  Effective Time,  all  rights  to  indemnification and
advancement of expenses existing in favor  of the directors and officers of  P-B
(the  "Indemnified Parties") under the provisions existing on the date hereof of
the Certificate of Incorporation, By-Laws and indemnification agreements of  P-B
shall survive the Effective Time, and Nellcor and the Surviving Corporation each
agrees  to indemnify and advance expenses to the Indemnified Parties to the full
extent required or permitted under the provisions existing on the date hereof of
P-B's Certificate of Incorporation and By-Laws and indemnification agreements of
P-B.
    

   
____(b)_For a  period of  six  years after  the  Effective Time,  Nellcor  shall
maintain,  with respect  to claims arising  from facts or  events which occurred
before the Effective Time, officers' and directors' liability insurance covering
the Indemnified  Parties  who are  currently  covered (in  their  capacities  as
officers  and directors)  by P-B's  existing officers'  and directors' liability
insurance policies, on terms substantially no less advantageous to such officers
and directors than such existing insurance.
    

   
____7.10__PUBLIC ANNOUNCEMENTS.__The  initial  press release  relating  to  this
Agreement  shall  be a  joint  press release  and  thereafter, so  long  as this
Agreement is in effect, Nellcor and Sub, on the one hand, and P-B, on the  other
hand,  agree that they will each obtain the approval of the other party prior to
issuing any  press release  or any  other written  communication (including  any
written communication to employees) and that they will use their best efforts to
consult  with  one  another  before otherwise  making  any  public  statement or
responding  to  any  press  inquiry  with  respect  to  this  Agreement  or  the
transactions  contemplated  hereby, except  as  may be  required  by law  or any
governmental agency if  required by  such agency or  the rules  of the  National
Association of Securities Dealers, Inc.
    

   
____7.11__EXPENSES.__Except  as provided in Section  9.3, all costs and expenses
incurred in connection  with this  Agreement and  the transactions  contemplated
hereby  (whether or not  the Merger is  consummated) shall be  paid by the party
incurring   such    expenses,   except    that   if    the   Merger    is    not
    

                                      A-37
<PAGE>
   
consummated  Nellcor  and  P-B  shall share  equally  the  expenses  incurred in
connection with  filings under  the  HSR Act,  printing  and mailing  the  Proxy
Statement and all aspects of the Registration Statement.
    

   
____7.12__ADDITIONAL AGREEMENTS.
    
   
____(a)_Subject to the terms and conditions herein provided, each of the parties
hereto  agrees to use all reasonable efforts to  take, or cause to be taken, all
action and to do, or cause to be done, all things necessary, proper or advisable
under applicable  laws and  regulations  to consummate  and make  effective  the
transactions  contemplated  by this  Agreement,  including using  all reasonable
efforts to obtain all necessary waivers,  consents and approvals, and to  effect
all  necessary registrations and filings and  to obtain from each natural person
who owns of record any  shares of the capital stock  of any subsidiary of P-B  a
power of attorney, in form acceptable to Nellcor and its counsel, appointing one
or  more  representatives  of  Nellcor  as attorney  in  fact  for  such person,
effective as of the Effective Time, for purposes of executing any documents  and
taking any other actions required to transfer record ownership of such shares to
such  entity as Nellcor shall determine. In case at any time after the Effective
Time any further action is necessary or  desirable to carry out the purposes  of
this  Agreement, the  proper officers and/or  directors of Nellcor,  Sub and P-B
shall take all such necessary action.
    

   
____(b)_Nellcor and  P-B  each will  cooperate  with  one another  and  use  all
reasonable efforts to prepare all necessary documentation to effect promptly all
necessary  filings  and to  obtain all  necessary permits,  consents, approvals,
orders and  authorizations  of or  any  exemptions  by, all  third  parties  and
governmental  bodies necessary  to consummate  the transactions  contemplated by
this Agreement.
    

   
____(c)_Each party  will keep  the other  party apprised  of the  status of  any
inquiries made of such party by the Department of Justice, the SEC, or any other
governmental  agency or  authority or  members of  their respective  staffs with
respect to this Agreement or the transactions contemplated herein.
    

   
____7.13__P-B ACCRUALS  AND  RESERVES.__Prior to  the  Closing Date,  P-B  shall
review  and, to  the extent determined  necessary or  advisable, consistent with
generally accepted accounting principles  and the accounting rules,  regulations
and  interpretations of the  SEC and its  staff, modify and  change its accrual,
reserve and  provision  policies and  practices  to (a)  reflect  the  Surviving
Corporation's  plans with respect to the conduct of P-B's business following the
Merger and (b)  make adequate  provision (for  the costs  and expenses  relating
thereto)  so as to be applied consistently on a mutually satisfactory basis with
those  of  Nellcor.  The  parties  agree  to  cooperate  in  preparing  for  the
implementation   of  the   adjustments  contemplated   by  this   Section  7.13.
Notwithstanding the foregoing,  (i) P-B shall  not be obligated  to take in  any
respect  any such action pursuant  to this Section 7.13  (other than pursuant to
the  preceding  sentence)  unless  and  until  Nellcor  acknowledges  that   all
conditions  to its obligation  to consummate the Merger  have been satisfied and
(ii) the Exchange Ratio shall be  determined for all purposes of this  Agreement
without  taking into  account any  adjustments made solely  as a  result of this
Section 7.13.
    

   
____7.14__CERTAIN GOVERNANCE MATTERS.
    
   
____(a)_Nellcor's Board of Directors shall  take all action necessary to  submit
to  the stockholders of Nellcor, for approval  at the special meeting of Nellcor
stockholders  referred  to  in  Section   7.4(a),  an  amendment  to   Nellcor's
Certificate  of Incorporation to change Nellcor's  name at the Effective Time or
promptly thereafter to Nellcor Puritan Bennett Incorporated. Nellcor's Board  of
Directors  shall take all action  necessary to cause (i)  one person selected by
Nellcor, prior to the mailing of  the Proxy Statement described in Section  7.4,
who  is  mutually agreeable  to  P-B and  is not  a  current or  former officer,
director or employee  of P-B,  (ii) one  person selected  by P-B,  prior to  the
mailing  of  the  Proxy Statement  described  in  Section 7.4,  who  is mutually
agreeable to Nellcor and is a current director of P-B, and (iii) Burton A. Dole,
Jr. ("Dole"), each to be elected as directors of Nellcor for a term expiring  at
the  next annual meeting of Nellcor's stockholders following the Effective Time.
If prior to the Effective Time, either Dole or such person selected pursuant  to
clause  (ii) above shall decline or be unable to serve as a director of Nellcor,
P-B  shall   designate   another  person   who   is  a   current   director   of
    

                                      A-38
<PAGE>
   
P-B to serve in such person's stead; provided such designated person is mutually
agreeable  to Nellcor. In addition, the Board of Directors of Nellcor shall take
all action necessary  to nominate  and endorse  such persons  for reelection  as
directors  of  Nellcor at  the  first annual  meeting  of Nellcor  following the
Effective Time.
    

   
____(b)_P-B agrees that (i) it will  terminate the employment of Dole  effective
at  the Effective  Time, (ii)  it will obtain  from Dole  an agreement modifying
certain employee benefits effective  as of the  Effective Time in  substantially
the form set forth in SCHEDULE 7.14(B)(I), and (iii) in connection therewith the
Surviving  Corporation shall be  bound by the terms  of the employment agreement
between Dole and P-B dated April 25, 1980 pursuant to which it shall pay to  him
the  amounts specified in Section  2.2 therein. Nellcor agrees  to offer to Dole
employment as an officer of Nellcor  pursuant to a written employment  agreement
reflecting the terms attached as SCHEDULE 7.14(B)(II) hereto.
    

   
____(c)_P-B  agrees that (i)  it will obtain  from John H.  Morrow ("Morrow") an
agreement  cancelling  his  existing  employment  agreement  effective  at   the
Effective  Time in substantially the form set forth in SCHEDULE 7.14(C)(I), (ii)
it will  obtain from  Morrow an  agreement modifying  certain employee  benefits
effective  as  of  the  Effective  Time  on  the  terms  set  forth  in SCHEDULE
7.14(C)(II), and (iii) in connection therewith Nellcor agrees to offer to Morrow
employment pursuant  to  the  terms  of the  Employment  Agreement  attached  as
SCHEDULE 7.14(C)(III) hereto.
    

   
                                  ARTICLE VIII
                    CONDITIONS TO CONSUMMATION OF THE MERGER
    

   
____8.1__CONDITIONS  TO  EACH  PARTY'S  OBLIGATION  TO  EFFECT  THE MERGER.__The
respective obligations of each  party to effect the  Merger shall be subject  to
the  satisfaction at or prior to the Effective Time of the following conditions,
any one of which may be waived by both P-B and Nellcor:
    

   
____(a)_Any waiting period applicable  to the consummation  of the Merger  under
the HSR Act shall have expired or been terminated.
    

   
____(b)_The  Registration Statement  shall have  become effective  in accordance
with the  provisions  of the  Securities  Act, and  shall  be effective  at  the
Effective  Time, and no stop order  suspending effectiveness of the Registration
Statement shall have been issued, no action, suit, proceedings or  investigation
by the SEC to suspend the effectiveness thereof shall have been initiated and be
continuing,  and all necessary approvals under state securities laws relating to
the issuance  or  trading of  the  Nellcor Common  Stock  to be  issued  to  P-B
stockholders in connection with the Merger shall have been received.
    

   
____(c)_This  Agreement and the transactions contemplated hereby shall have been
approved and adopted (i) by  the favorable vote of a  majority of the shares  of
outstanding  capital stock  of Nellcor casting  votes thereon  at a stockholders
meeting at which a  quorum is present  in accordance with the  DGCL in order  to
satisfy   the   stockholder   approval  requirements   of   Part   III,  Section
5(i)(1)(c)(ii) of Schedule D  of the NASD Manual  applicable to Nasdaq  National
Market  issuers, and (ii) by  the favorable vote of a  majority of the shares of
outstanding capital stock  of P-B entitled  to vote thereon  in accordance  with
Section 251(c) of the DGCL.
    

   
____(d)_No  preliminary or permanent  injunction or other  order by any federal,
state  or  foreign   court  of  competent   jurisdiction  which  prohibits   the
consummation  of the  Merger shall  have been  issued and  remain in  effect. No
statute, rule, regulation, executive order, stay, decree, or judgment shall have
been  enacted,  entered,  issued,  promulgated  or  enforced  by  any  court  or
governmental  authority  which prohibits  or restricts  the consummation  of the
Merger. Other than the filing of the Certificate of Merger with the Secretary of
State of  Delaware, all  authorizations, consents,  orders or  approvals of,  or
declarations or filings with, and all expirations of waiting periods imposed by,
any  governmental entity (all of the  foregoing, "Consents") which are necessary
for the consummation of  the Merger, other than  Consents the failure to  obtain
which   would  not  materially,   adversely  affect  the   consummation  of  the
    

                                      A-39
<PAGE>
   
Merger or  in the  aggregate have  a Material  Adverse Effect  on the  Surviving
Corporation  and  its subsidiaries,  taken as  a whole,  shall have  been filed,
occurred or been obtained (all such permits, approvals, filings and consents and
the lapse  of all  such waiting  periods  being referred  to as  the  "Requisite
Regulatory  Approvals") and all such Requisite  Regulatory Approvals shall be in
full force and effect. Nellcor shall have received all state securities or  blue
sky  permits and other  authorizations necessary to issue  the shares of Nellcor
Common Stock in exchange for  the shares of P-B  Common Stock and to  consummate
the Merger.
    

   
____(e)_There shall not be any action taken, or any statute, rule, regulation or
order  enacted, entered,  enforced or  deemed applicable  to the  Merger, by any
federal or state governmental  entity which, in connection  with the grant of  a
Requisite  Regulatory Approval,  imposes any  condition or  restriction upon the
Surviving Corporation or its subsidiaries (or, in the case of any disposition of
assets required  in connection  with such  Requisite Regulatory  Approval,  upon
Nellcor  or its  subsidiaries or  P-B or  its subsidiaries),  including, without
limitation, requirements relating  to the  disposition of assets,  which in  any
such case would so materially adversely impact the economic or business benefits
of  the transactions contemplated by this Agreement as to render inadvisable the
consummation of the Merger.
    

   
____(f)_Nellcor and P-B  shall have  received (i)  a letter,  dated the  Closing
Date,  addressed to Nellcor from Price Waterhouse,  in response to a letter from
Nellcor summarizing  the relevant  facts and  in form  and substance  reasonably
satisfactory  to Nellcor, a copy  of which shall be provided  to P-B, and (ii) a
letter, dated the Closing Date, addressed to P-B from Ernst & Young, in response
to a letter from P-B  summarizing the relevant facts  and in form and  substance
reasonably  satisfactory to P-B, a  copy of which shall  be given to Nellcor, in
each case to  the effect that  the Merger qualifies  for "pooling of  interests"
treatment for financial reporting purposes and that such accounting treatment is
in  accordance with  generally accepted accounting  principles. Price Waterhouse
shall also have  received from Ernst  & Young,  a letter in  form and  substance
satisfactory  to Price Waterhouse, that  Ernst & Young is  not aware of any fact
concerning P-B  or  any of  its  affiliates  that would  preclude  Nellcor  from
accounting  for the  Merger by the  "pooling of interests"  method for financial
reporting purposes.
    

   
____8.2__CONDITIONS TO OBLIGATION OF P-B  TO EFFECT THE MERGER.__The  obligation
of  P-B to effect the Merger shall be  further subject to the satisfaction at or
prior to the Effective Time of the following additional conditions, which may be
waived by P-B:
    

   
____(a)_Each of Nellcor and  Sub shall have performed  in all material  respects
its  obligations under this Agreement required to be performed by it at or prior
to the Effective Time and the representations and warranties of Nellcor and  Sub
contained  in this Agreement shall be true  and correct in all material respects
at and as of the  Effective Time as if  made at and as  of such time, except  as
contemplated by this Agreement, and P-B shall have received a certificate of the
President  or an Executive Vice  President of Nellcor as  to the satisfaction of
this condition.
    

   
____(b)_P-B shall have received an opinion of Blackwell Sanders Matheny Weary  &
Lombardi  L.C., counsel  to P-B,  dated the  Closing Date,  substantially to the
effect that, on the basis of  facts, representations, and assumptions set  forth
in  such opinion which  are consistent with  the state of  facts existing at the
Closing Date, the Merger will  be treated for federal  income tax purposes as  a
reorganization within the meaning of Section 368(a) of the Code and that Nellcor
and P-B will each be a party to the reorganization within the meaning of Section
368(b) of the Code. In rendering any such opinion, such counsel may require and,
to the extent they deem necessary and appropriate, may rely upon representations
made  in  certificates  of officers  of  Nellcor,  Sub, P-B,  affiliates  of the
foregoing and others. In  addition, P-B shall have  received the opinion,  dated
the  Closing Date,  of Morrison  & Foerster,  counsel for  Nellcor, covering the
matters set forth in EXHIBIT 8.2(B).
    

   
____(c)_Nellcor shall have obtained the consent or approval of each person whose
consent or  approval  shall be  required  in connection  with  the  transactions
contemplated  hereby  under  any  loan  or  credit  agreement,  note,  mortgage,
indenture, lease,  license  or  other  agreement  or  instrument,  except  those
    

                                      A-40
<PAGE>
   
for  which failure  to obtain such  consents and approvals  would not materially
adversely affect the consummation of the transactions contemplated hereby or  in
the  aggregate have a  Material Adverse Effect on  the Surviving Corporation and
its subsidiaries taken as a whole.
    

   
____(d)_There shall not have occurred following  the date of this Agreement  and
prior  to the  Closing Date  any change,  or any  event involving  a prospective
change, in  Nellcor's  business,  assets,  financial  condition  or  results  of
operation  which has had,  or is reasonably  likely to have,  in the aggregate a
Material Adverse Effect (other than as  a result of changes or proposed  changes
in  federal or state  health care (including health  care reimbursement) laws or
regulations of  general applicability  or  interpretations thereof,  changes  in
generally  accepted  accounting principles  and  changes that  could,  under the
circumstances, reasonably have been anticipated in light of disclosures made  in
writing by Nellcor to P-B prior to the execution of this Agreement).
    

   
____8.3__CONDITIONS TO OBLIGATIONS OF NELLCOR AND SUB TO EFFECT THE MERGER.__The
obligations  of Nellcor and Sub to effect the Merger shall be further subject to
the satisfaction at or prior to  the Effective Time of the following  additional
conditions, which may be waived by Nellcor:
    

   
____(a)_P-B  shall have performed in all material respects its obligations under
this Agreement required to be performed and  complied with by it at or prior  to
the  Effective Time and  the representations and warranties  of P-B contained in
this Agreement shall be true and correct  in all material respects at and as  of
the  Effective Time as if made at and as of such time, except as contemplated by
this Agreement, and  Nellcor and Sub  shall have received  a Certificate of  the
Chairman  of the Board or an Executive or Senior Vice President of P-B as to the
satisfaction of this condition.
    

   
____(b)_P-B shall have  obtained the consent  or approval of  each person  whose
consent  or approval shall be required in  order to permit the succession by the
Surviving Corporation  pursuant  to  the  Merger to  any  obligation,  right  or
interest  of P-B  or any  subsidiary under any  loan or  credit agreement, note,
mortgage, indenture, lease,  license or  other agreement  or instrument,  except
those  for  which  failure  to  obtain such  consents  and  approvals  would not
materially adversely affect  the consummation of  the transactions  contemplated
hereby  or in  the aggregate  have a  Material Adverse  Effect on  the Surviving
Corporation and its subsidiaries taken as a whole.
    

   
____(c)_Nellcor shall have received the opinion of Morrison & Foerster,  counsel
to Nellcor, dated the Closing Date and addressed to Nellcor, to the effect that,
on  the  basis of  facts,  representations, and  assumptions  set forth  in such
opinion which are consistent with the  state of facts existing at the  Effective
Time,  the  Merger  will  be  treated  for  federal  income  tax  purposes  as a
reorganization within  the meaning  of  Section 368(a)  of  the Code,  and  that
Nellcor  and P-B will each be a  party to that reorganization within the meaning
of Section 368(b) of the Code. In  rendering any such opinion, such counsel  may
require  and, to the extent  they deem necessary and  appropriate, may rely upon
representations  made  in  certificates  of  officers  of  P-B,  Nellcor,   Sub,
affiliates of the foregoing and others. In addition, Nellcor shall have received
the  opinion, dated  the Closing Date,  of Blackwell, Sanders,  Matheny, Weary &
Lombardi L.C.,  counsel for  P-B,  covering the  matters  set forth  in  EXHIBIT
8.3(C).
    

   
____(d)_There  shall not have occurred following  the date of this Agreement and
prior to  the Closing  Date any  change, or  any event  involving a  prospective
change,  in P-B's business, assets, financial  condition or results of operation
which has had,  or is reasonably  likely to  have, in the  aggregate a  Material
Adverse Effect (other than as a result of changes or proposed changes in federal
or  state health care (including health  care reimbursement) laws or regulations
of general  applicability  or  interpretations  thereof,  changes  in  generally
accepted  accounting principles and changes that could, under the circumstances,
reasonably have been anticipated in light of disclosures made in writing by  P-B
to Nellcor prior to the execution of this Agreement).
    

                                      A-41
<PAGE>
                                   ARTICLE IX
                       TERMINATION, AMENDMENT AND WAIVER

    9.1    TERMINATION.    This  Agreement  may  be  terminated  and  the Merger
contemplated hereby abandoned at any time  prior to the Effective Time,  whether
before or after approval by the stockholders of P-B or Nellcor:

    (a) by mutual written consent of Nellcor, Sub and P-B;

    (b)  by either Nellcor and Sub, on the  one hand, or P-B, on the other hand,
if the Merger shall not have been consummated on or before December 31, 1995;

    (c) by P-B if there shall have been any material breach of a  representation
and  warranty or material  obligation of Nellcor  or Sub hereunder  and, if such
breach is curable,  such default  shall have not  been remedied  within 10  days
after  receipt by Nellcor of  notice in writing from  P-B specifying such breach
and requesting that it be remedied; PROVIDED,  that such 10 day period shall  be
extended  for so long as Nellcor or  Sub shall be making all reasonable attempts
to cure such breach, unless the breach is not susceptible of a cure;

    (d) by Nellcor and  Sub if there  shall have been any  material breach of  a
representation and warranty or material obligation of P-B hereunder and, if such
breach  is curable,  such default  shall not have  been remedied  within 10 days
after receipt by P-B of  notice in writing from  Nellcor or Sub specifying  such
breach  and requesting that  it be remedied;  PROVIDED, that such  10 day period
shall be extended for so long as P-B shall be making all reasonable attempts  to
cure such breach, unless the breach is not susceptible of a cure;

    (e)  by Nellcor if the Board of Directors of P-B shall have (i) withdrawn or
modified in  a manner  adverse to  Nellcor its  approval or  recommendation  (or
failed  to make such recommendation)  of this Agreement or  the Merger, or shall
have resolved to  do any of  the foregoing, or  (ii) recommended an  Acquisition
Proposal other than the Merger;

    (f)  by P-B if the Board of Directors of Nellcor shall have (i) withdrawn or
modified in a manner adverse to P-B its approval or recommendation (or failed to
make such  recommendation)  of this  Agreement  or  the Merger,  or  shall  have
resolved to do any of the foregoing, or (ii) recommended an Acquisition Proposal
other than the Merger;

    (g)  by either Nellcor or P-B if  any court of competent jurisdiction in the
United States or  other United  States governmental  body shall  have issued  an
order,  decree or  ruling or  taken any  other action  restraining, enjoining or
otherwise prohibiting the  Merger and such  order, decree, ruling  or any  other
action  shall have  become final  and non-appealable;  PROVIDED, that  the party
seeking to terminate this Agreement pursuant to this clause (g) shall have  used
all reasonable efforts to remove such order, decree or ruling;

    (h)  by  Nellcor,  upon  written  notice to  P-B,  if  any  approval  of the
stockholders of P-B required  for the consummation of  the Merger submitted  for
approval  shall not have  been obtained by  reason of the  failure to obtain the
required vote  at a  duly held  meeting of  stockholders or  at any  adjournment
thereof;

    (i)  by P-B, upon written notice to Nellcor  and Sub, if any approval of the
stockholders of Nellcor required  for the consummation  of the Merger  submitted
for approval shall not have been obtained by reason of the failure to obtain the
required  vote at  a duly  held meeting  of stockholders  or at  any adjournment
thereof; or

    (j)  by (i) Nellcor, if its Board of Directors, in the exercise of its  good
faith  judgment as to its fiduciary  duties to its stockholders under applicable
law as  advised by  independent  counsel, determines  that such  termination  is
required  by reason of  another Acquisition Proposal being  made with respect to
Nellcor, or (ii) P-B,  if its Board  of Directors, in the  exercise of its  good
faith judgment as to its

                                      A-42
<PAGE>
fiduciary  duties  to  its  stockholders  under  applicable  law  as  advised by
independent counsel, determines that such  termination is required by reason  of
another Acquisition Proposal being made with respect to P-B.

    9.2   EFFECT OF TERMINATION.  In  the event of termination of this Agreement
as provided above, this  Agreement shall forthwith become  of no further  effect
and,  except  for a  termination  resulting from  a breach  by  a party  of this
Agreement, there  shall be  no liability  or obligation  on the  part of  either
Nellcor,  Sub or P-B  or their respective  officers or directors  (except as set
forth in Section 7.1(b) hereof and except for Sections 7.11, 9.3, 10.2 and  10.6
hereof  which  shall  survive  the  termination).  Moreover,  in  the  event  of
termination of  this Agreement  pursuant to  Section 9.1(c)  or 9.1(d),  nothing
herein  shall  prejudice the  ability of  the  non-breaching party  from seeking
damages from  any other  party  for any  breach  of this  Agreement,  including,
without limitation, attorneys' fees and the right to pursue any remedy at law or
in equity. Upon request therefor, each party will redeliver or, at the option of
the  party receiving such request, destroy  all documents, work papers and other
material of any other  party relating to  the transactions contemplated  hereby,
whether  obtained before or after the  execution hereof, to the party furnishing
same.

    9.3  CANCELLATION FEES; EXPENSES.

    (a) If at any time (i) P-B  shall have entered into an agreement,  including
without  limitation an  agreement in principle,  with respect  to an Acquisition
Proposal, other than the Merger contemplated  by this Agreement; (ii) P-B  shall
breach  any of the provisions of Section 7.2 above or shall recommend or approve
an Acquisition Proposal pursuant to Section 7.2; or (iii) any person, entity  or
group  of  persons  or  entities  acting  in  concert  shall  acquire beneficial
ownership of more than fifty percent (50%) of the voting securities of P-B as  a
result  of  an  Acquisition Proposal  and,  in the  case  of (i)  or  (ii), this
Agreement is  terminated pursuant  to Section  9.1(d), Section  9.1(e),  Section
9.1(h) or Section 9.1(j)(ii); then Nellcor shall be entitled to be paid by P-B a
fee  in  cash  or  immediately  available  funds  of  ten  million  U.S. dollars
($10,000,000) (the "P-B Cancellation Fee").

    (b) P-B shall pay  to Nellcor the P-B  Cancellation Fee provided in  Section
9.3(a) above within ten (10) days of written demand therefor by the Nellcor. The
payment  of the  P-B Cancellation  Fee shall  be conditioned  on there  being no
material breach of the obligations of Nellcor and Sub hereunder. If P-B fails to
pay any amount due Nellcor pursuant to this Section 9.3 when due, P-B shall  pay
interest  thereon, from the date  due until the date paid  in full, at the Prime
Rate as announced from time to time by Bank of America or any successor  thereto
(the  "Prime Rate")  and shall reimburse  Nellcor for  all reasonable attorneys'
fees and other costs and expenses incurred by Nellcor in collecting such  amount
from P-B.

    (c)  Notwithstanding anything  herein to  the contrary,  payment of  the P-B
Cancellation Fee as  provided in  subsections (a) and  (b) of  this Section  9.3
shall  constitute full settlement of any  and all liabilities and obligations of
P-B  under  this  Agreement,  except  for  liabilities  arising  from  fraud  or
intentional  misrepresentation with respect to this  Agreement by P-B and except
as provided in subsection (d).

    (d) In  the event  that  either P-B  or  Nellcor terminates  this  Agreement
pursuant  to, respectively,  Section 9.1(c) or  Section 9.1(d)  hereof, then the
nonterminating party shall pay to the terminating party two million U.S. dollars
($2,000,000) representing  full payment  of the  terminating party's  reasonable
out-of-pocket  expenses incurred  in connection with  the negotiation, execution
and performance of this  Agreement ("Expense Reimbursement Payment");  PROVIDED,
HOWEVER,  that  the  terminating party  shall  not  be entitled  to  any Expense
Reimbursement Payment  pursuant  to  this  Section 9.3(d)  if  at  the  time  of
termination  the nonterminating party also would have been entitled to terminate
this Agreement pursuant to Section 9.1(c)  or Section 9.1(d), as applicable.  In
addition,  if the stockholders of Nellcor or  P-B fail to approve the Merger and
this Agreement is  terminated by P-B  or Nellcor pursuant  to Section 9.1(h)  or
9.1(i),  as the case may be, then the party whose stockholders have so failed to
approve the Merger shall pay to the other party hereto the Expense Reimbursement
Payment; PROVIDED, HOWEVER, that no such Expense Reimbursement Payment shall  be
due under this

                                      A-43
<PAGE>
sentence  if  the stockholders  of  the party  which  would have  otherwise been
entitled to such Expense Reimbursement Payment have previously failed to approve
the Merger at the stockholders meeting called for that purpose.  Notwithstanding
the  foregoing, the parties hereby acknowledge that  they do not intend that any
party hereto would be entitled to bring a claim against another party hereto for
negligent misrepresentation in connection with the breach of any representations
made herein by such other party.

    (e) If  at  any time  (i)  Nellcor shall  have  entered into  an  agreement,
including  without  limitation an  agreement in  principle,  with respect  to an
Acquisition Proposal, other than the Merger contemplated by this Agreement; (ii)
Nellcor shall  breach  any of  the  provisions of  Section  7.2 above  or  shall
recommend  or approve an Acquisition Proposal  pursuant to Section 7.2; or (iii)
any entity,  person or  group of  persons or  entities acting  in concert  shall
acquire  beneficial ownership  of more  than fifty  percent (50%)  of the voting
securities of Nellcor as a result of  an Acquisition Proposal, and, in the  case
of (i) or (ii), this Agreement is terminated pursuant to Section 9.1(c), Section
9.1(f),  Section 9.1(i) or Section  9.1(j)(i); then P-B shall  be entitled to be
paid by Nellcor a fee in cash or immediately available funds of ten million U.S.
dollars ($10,000,000) (the "Nellcor Cancellation Fee").

    (f) Nellcor  shall pay  to  P-B the  Nellcor  Cancellation Fee  provided  in
Section 9.3(e) above within ten (10) days of written demand therefor by P-B. The
payment  of the Nellcor Cancellation Fee shall  be conditioned on there being no
material breach of the obligations of P-B hereunder. If Nellcor fails to pay any
amount due P-B pursuant to this Section 9.3 when due, Nellcor shall pay interest
thereon, from the date due  until the date paid in  full, at the Prime Rate  and
shall  reimburse  P-B for  all reasonable  attorneys' fees  and other  costs and
expenses incurred by P-B in collecting such amount from Nellcor.

    (g) Notwithstanding anything herein to the contrary, payment of the  Nellcor
Cancellation  Fee as  provided in  subsections (e) and  (f) of  this Section 9.3
shall constitute full settlement of any  and all liabilities and obligations  of
Nellcor  under  this Agreement,  except for  liabilities  arising from  fraud or
intentional misrepresentation  with respect  to this  Agreement by  Nellcor  and
except as provided in subsection (d).

    9.4   AMENDMENT.  This Agreement may  be amended by action taken by Nellcor,
Sub and P-B at any time before  or after approval hereof by the stockholders  of
P-B  and Nellcor, but, after any such approval, no amendment shall be made which
alters the Exchange Ratio or which  in any way materially adversely affects  the
rights  of such stockholders, without the further approval of such stockholders.
This Agreement may not be amended except  by an instrument in writing signed  on
behalf of each of the parties hereto.

    9.5    EXTENSION; WAIVER.   At  any time  prior to  the Effective  Time, the
parties hereto  may (a)  extend  the time  for the  performance  of any  of  the
obligations   or  other  acts  of  the  other  parties  hereto,  (b)  waive  any
inaccuracies in the representations  and warranties contained  herein or in  any
document  delivered pursuant  hereto, and (c)  waive compliance with  any of the
agreements or conditions contained herein. Any agreement on the part of a  party
hereto  to any such extension or  waiver shall be valid only  if set forth in an
instrument in writing  signed on  behalf of such  party. Such  waiver shall  not
operate  as a waiver  of, or estoppel  with respect to,  any subsequent or other
failure.

                                   ARTICLE X
                               GENERAL PROVISIONS

    10.1    SURVIVAL  OF  REPRESENTATIONS,   WARRANTIES  AND  AGREEMENTS.     No
representations,  warranties or agreements contained herein shall survive beyond
the Effective Time except  that the agreements contained  in Sections 2.3,  3.1,
3.2,  3.3, 3.4,  3.5, 3.7,  7.8, 7.9,  7.12(a), 7.14,  9.3, 10.1,  10.6 and 10.7
hereof shall  survive beyond  the  Effective Time,  and  the agreements  of  the
"affiliates"  of Nellcor and P-B delivered pursuant to Section 6.7 shall survive
beyond the Effective Time.

                                      A-44
<PAGE>
    10.2  BROKERS.

    (a) P-B represents and warrants to Nellcor and Sub that, (i) except for  its
financial  advisor, Smith Barney Inc., no broker, finder or financial advisor is
entitled to any  brokerage, finder's or  other fee or  commission in  connection
with  the Merger or  the transactions contemplated by  this Agreement based upon
arrangements made by or on  behalf of P-B and (ii)  a true and complete copy  of
all  engagement  letters or  agreements between  P-B and  Smith Barney  Inc. and
between P-B and  any third party  for whom any  amounts payable contingent  upon
consummation of the Merger, have previously been delivered to Nellcor.

    (b)  Nellcor  represents  and  warrants  to P-B  that,  (i)  except  for its
financial advisors, Robertson,  Stephens &  Company, L.P. and  Goldman, Sachs  &
Co.,  no  broker, finder  or  financial advisor  is  entitled to  any brokerage,
finder's or  other  fee or  commission  in connection  with  the Merger  or  the
transactions  contemplated by this Agreement based  upon arrangements made by or
on behalf of Nellcor or Sub and (ii) a true and complete copy of the  engagement
letters  or agreements among Nellcor and Robertson, Stephens & Company, L.P. and
Goldman, Sachs  & Co.  and between  Nellcor and  any third  party for  whom  any
amounts  payable are contingent upon consummation of the Merger, have previously
been delivered to P-B.

    10.3   NOTICES.   All  notices,  claims, demands  and  other  communications
hereunder  shall be in writing and shall be deemed given if delivered personally
or by  telex or  telecopy or  mailed by  registered or  certified mail  (postage
prepaid,  return receipt requested)  to the respective  parties at the following
addresses (or at such other  address for a party as  shall be specified by  like
notice):

    (a) If to Nellcor or Sub, to:
       Nellcor Incorporated
       4280 Hacienda Drive
       Pleasanton, California 94288
       Attention: Laureen DeBuono, Esq.
                 Vice President of
                 Human Resources, General
                 Counsel and Corporate
                 Secretary

       with a copy to:

        Morrison & Foerster
       Twelfth Floor
       19900 McArthur Boulevard
       Irvine, California 92715
       Attention: Robert M. Mattson, Jr., Esq.

       and

        Morrison & Foerster
       345 California Street
       San Francisco, California 94104
       Attention: Gavin B. Grover, Esq.

    (b) if to P-B, to:
       Puritan-Bennett Corporation
       9401 Indian Creek Parkway
       Overland Park, Kansas 66225
       Attention: Burton A. Dole, Jr.
                 Chairman, President and
                 Chief Executive Officer

                                      A-45
<PAGE>
       with a copy to:

        Blackwell Sanders Matheny
         Weary & Lombardi L.C.
       Suite 1100
       Two Pershing Square
       2300 Main Street
       Kansas City, Missouri 64108
       Attention: Daniel C. Weary, Esq.

    10.4   DESCRIPTIVE HEADINGS.   The headings contained  in this Agreement are
for reference purposes  only and  shall not  affect in  any way  the meaning  or
interpretation of this Agreement.

    10.5  ENTIRE AGREEMENT; ASSIGNMENT.  This Agreement (including the Exhibits,
and  other documents and instruments referred to herein) and the Confidentiality
Agreement (a) constitute  the entire  agreement and supersedes  all other  prior
agreements  and understandings, both written and  oral, among the parties or any
of them, with respect to the subject matter hereof; (b) except for Sections 7.8,
7.9 and 7.14,  is not intended  to confer upon  any other person  any rights  or
remedies  hereunder;  and (c)  shall  not be  assigned  by operation  of  law or
otherwise, provided that Nellcor  or Sub may assign  its rights and  obligations
hereunder  to a direct or indirect subsidiary of Nellcor, but no such assignment
shall relieve Nellcor or Sub, as the case may be, of its obligations hereunder.

    10.6  GOVERNING LAW.  This Agreement  shall be governed by and construed  in
accordance  with the laws of the State  of Delaware without giving effect to the
provisions thereof relating to conflicts of law.

    10.7  PARTIES IN INTEREST.   Except for Sections  7.8, 7.9 and 7.14  hereof,
nothing  in this Agreement, express  or implied, is intended  to or shall confer
upon any other person any rights, benefits or remedies of any nature  whatsoever
or by reason of this Agreement.

    10.8    COUNTERPARTS.    This  Agreement may  be  executed  in  two  or more
counterparts, each of which shall be deemed  to be an original but all of  which
shall constitute one and the same agreement.

    10.9  VALIDITY.  The invalidity or unenforceability of any provision of this
Agreement  shall  not  effect  the  validity  or  enforceability  of  any  other
provisions of this Agreement, which shall remain in full force and effect.

    10.10  JURISDICTION  AND VENUE.   Each party hereto  hereby agrees that  any
proceeding relating to this Agreement and the Merger shall be brought in a state
court of Delaware. Each party hereto hereby consents to personal jurisdiction in
any  such action  brought in  any such  Delaware court,  consents to  service of
process by  registered mail  made upon  such party  and such  party's agent  and
waives  any objection to venue  in any such Delaware court  or to any claim that
such Delaware court is an inconvenient forum.

    10.11   INVESTIGATION.    The  respective  representations  of  warranty  of
Nellcor,  Sub and P-B contained herein or in the certificates or other documents
delivered prior to the Closing shall not be deemed waived or otherwise  affected
by any investigation made by any party hereto.

    10.12  CONSENTS.  For purposes of any provision of this Agreement requiring,
permitting  or providing for the consent of  Nellcor or P-B, the written consent
of the Chief Executive Officer  of Nellcor or P-B, as  the case may be shall  be
sufficient to constitute such consent.

                                      A-46
<PAGE>
    IN  WITNESS WHEREOF, each of Nellcor, Sub  and P-B has caused this Agreement
to be executed on its behalf by  its officers thereunto duly authorized, all  as
of the date first above written.

NELLCOR INCORPORATED
By: /S/ C. RAYMOND LARKIN, JR.
    ------------------------------------------
    Name: C. Raymond Larkin, Jr.
    Title: President and Chief
    Executive Officer

                                          PUMA MERGER CORPORATION

                                          By: /S/ C. RAYMOND LARKIN, JR.
                                             -----------------------------------
                                             Name: C. Raymond Larkin, Jr.
                                             Title: President

                                          PURITAN-BENNETT CORPORATION

                                          By: /S/ BURTON A. DOLE, JR.
                                             -----------------------------------
                                             Name: Burton A. Dole, Jr.
                                             Title: Chairman, President
                                             and Chief Executive Officer

                                      A-47
<PAGE>
   
                                                                         ANNEX B
    

   
                AMENDMENT NO. 1 TO AGREEMENT AND PLAN OF MERGER
    

   
____This  Amendment No.  1 to Agreement  and Plan of  Merger (this "Amendment"),
dated as  of June  30, 1995,  is made  by and  between Nellcor  Incorporated,  a
Delaware   corporation   ("Nellcor"),  Puma   Merger  Corporation,   a  Delaware
corporation and wholly-owned subsidiary of Nellcor ("Sub"), and  Puritan-Bennett
Corporation, a Delaware corporation ("P-B").
    

   
____A.__The  parties to this Amendment have  entered into that certain Agreement
and Plan of Merger, dated as of May 21, 1995 (the "Merger Agreement"),  pursuant
to  which, on the terms and subject to  the conditions set forth therein, Sub is
to be merged with and into P-B  such that P-B becomes a wholly-owned  subsidiary
of Nellcor.
    

   
____B.__The parties desire to amend the Merger Agreement as set forth herein.
    

   
____Accordingly, the parties hereto agree as follows:
    

   
____1.__Section  7.14(a)  of the  Merger  Agreement is  amended  to read  in its
entirety as follows:
    

   
    ____"(a)_Nellcor's Board of  Directors shall  take all  action necessary  to
    submit  to the stockholders of Nellcor,  for approval at the special meeting
    of Nellcor  stockholders referred  to  in Section  7.4(a), an  amendment  to
    Nellcor's  Certificate  of Incorporation  to  change Nellcor's  name  at the
    Effective  Time   or  promptly   thereafter  to   Nellcor  Puritan   Bennett
    Incorporated.  Nellcor's Board of Directors  shall take all action necessary
    to cause (i) one person selected by  P-B, prior to the mailing of the  Proxy
    Statement described in Section 7.4, who is mutually agreeable to Nellcor and
    is a current director of P-B, and (ii) Burton A. Dole, Jr. ("Dole"), each to
    be  elected as directors of  Nellcor for a term  expiring at the next annual
    meeting of Nellcor's stockholders following the Effective Time. If prior  to
    the  Effective Time, either Dole or  such person selected pursuant to clause
    (i) above shall decline or be unable to serve as a director of Nellcor,  P-B
    shall  designate another person who is a current director of P-B to serve in
    such person's stead; provided such  designated person is mutually  agreeable
    to  Nellcor. In addition, the  Board of Directors of  Nellcor shall take all
    action necessary to nominate and  endorse such persons selected pursuant  to
    clause  (i) and  (ii) above  for reelection as  directors of  Nellcor at the
    first annual meeting of Nellcor following the Effective Time and to nominate
    for election  as an  additional  director of  Nellcor  at the  first  annual
    meeting  of  Nellcor following  the Effective  Time  one person  selected by
    Nellcor who is not a current or former officer, director or employee of  P-B
    and who is mutually agreeable to the persons selected pursuant to clause (i)
    and (ii) above."
    

   
____2.__Except  as set forth above, all provisions of the Merger Agreement shall
remain in full force and effect.
    

   
____3.__This Amendment may  be executed  in two  or more  counterparts, each  of
which  shall be deemed to  be an original but all  of which shall constitute one
and the same agreement.
    

   
____IN WITNESS WHEREOF, the parties have executed this Amendment as of the  date
first noted above.
    

   
                                          NELLCOR INCORPORATED
                                          By:_ ____/s/_C. RAYMOND LARKIN, JR.___
    
   

    
   
                                             -----------------------------------
    
   
                                                   C. Raymond Larkin, Jr.
                                                PRESIDENT AND CHIEF EXECUTIVE
                                                            OFFICER
    

                                      B-1
<PAGE>
   
                                          PUMA MERGER CORPORATION
                                          By:_ ____/s/_C. RAYMOND LARKIN, JR.___
    
   

    
   
                                             -----------------------------------
    
   
                                                   C. Raymond Larkin, Jr.
                                                          PRESIDENT
    

   
                                          PURITAN-BENNETT CORPORATION
                                          By:_ _____/s/_BURTON A. DOLE, JR._____
    
   

    
   
                                             -----------------------------------
    
   
                                                     Burton A. Dole, Jr.
                                                CHAIRMAN, PRESIDENT AND CHIEF
                                                       EXECUTIVE OFFICER
    

                                      B-2
<PAGE>
   
                                                                         ANNEX C
    

   
_ROBERTSON
STEPHENS &
_____COMPANY
    

   
                                                                    May 21, 1995
    

   
PRIVILEGED AND CONFIDENTIAL
    

   
Board of Directors
Nellcor Incorporated
4280 Hacienda Drive
Pleasanton, CA 94588
    

   
Members of the Board:
    

   
____You  have  asked  our  opinion  with  respect  to  the  fairness  to Nellcor
Incorporated ("Nellcor") and its  stockholders, from a  financial point of  view
and  as of  the date hereof,  of the Exchange  Ratio (as defined  below), in the
proposed merger of Puritan-Bennett Corporation ("Puritan-Bennett") with and into
Nellcor, pursuant to the Agreement and Plan of Merger, dated as of May 21,  1995
(the  "Agreement"). Under the terms of  the Agreement, a wholly-owned subsidiary
of  Nellcor  will   merge  with   and  into   Puritan-Bennett,  and   thereafter
Puritan-Bennett  will become a wholly-owned  subsidiary of Nellcor in accordance
with the Agreement (the "Merger"). In the Merger, each outstanding share of  the
common stock of Puritan-Bennett will be converted into the right to receive 0.88
shares  of  the  common stock  of  Nellcor (the  "Exchange  Ratio"). Outstanding
options to acquire shares of Puritan-Bennett  will vest on an accelerated  basis
at  closing and will be converted into options to acquire shares of Nellcor. The
Merger is intended to qualify as  a tax-free reorganization and to be  accounted
for  as a "pooling of interests." The terms and conditions of the Merger are set
out more fully in the Agreement.
    

   
____For purposes of this opinion we have: (i) reviewed financial information  on
Nellcor and Puritan-Bennett furnished to us by both companies, including certain
internal financial analyses and forecasts prepared by Nellcor's management; (ii)
reviewed  publicly  available  information;  (iii)  held  discussions  with  the
management of Nellcor  and Puritan-Bennett concerning  the businesses, past  and
current  business  operations,  results  of  regulatory  examinations, financial
condition and future  prospects of both  companies, independently and  combined,
including certain information prepared jointly by the managements of Nellcor and
Puritan-Bennett  concerning  potential  cost savings  and  synergies  that could
result from this  Merger; (iv) reviewed  the Agreement; (v)  reviewed the  stock
price  and trading histories of both companies; (vi) reviewed the exchange ratio
implied by historical  stock prices  of the  two companies;  (vii) reviewed  the
contribution  by  each  company to  pro  forma combined  revenue,  gross income,
research and development expenditures, operating  income, pretax income and  net
income;  (viii) reviewed  the valuations of  publicly traded  companies which we
deemed comparable to  Nellcor and Puritan-Bennett;  (ix) compared the  financial
terms  of  the Merger  with  other transactions  which  we deemed  relevant; (x)
prepared discounted cash flow analyses of both companies; (xi) analyzed the  pro
forma  earnings per  share of  the combined company;  and (xii)  made such other
studies and inquiries, and reviewed such other data, as we deemed relevant.
    

   
                                      C-1
    
<PAGE>
   
____In connection with our opinion,  we have not however independently  verified
any  of the foregoing information and have  relied on all such information being
complete and accurate in all material  respects. Furthermore, we did not  obtain
any independent appraisal of the properties or assets and liabilities of Nellcor
or  Puritan-Bennett  or  of  any  of their  subsidiaries.  With  respect  to the
financial and operating forecasts  (and the assumptions  and bases therefor)  of
Nellcor  and Puritan-Bennett which  we have reviewed, we  have assumed that such
forecasts have been reasonably prepared and reflect the best available estimates
and judgments  of such  respective  managements and  that such  projections  and
forecasts  will be  realized in  the amounts and  in the  time periods currently
estimated by  the  managements  of Nellcor  and  Puritan-Bennett.  In  addition,
Robertson  Stephens has relied  upon estimates and judgments  of Nellcor and P-B
managements as to the future financial performance of both companies,  including
the  cost savings and synergies resulting from the Merger. We also have assumed,
with your  consent, that  the  Merger will  be accounted  for  as a  pooling  of
interests  under generally accepted accounting principles. While we believe that
our review, as described within,  is an adequate basis  for the opinion that  we
express,  this opinion  is necessarily  based upon  market, economic,  and other
conditions that exist and can be evaluated as of the date of this letter, and on
information available to us as of the date hereof.
    

   
____Robertson, Stephens  &  Company is  familiar  with Nellcor  having  provided
certain  investment banking  services to  Nellcor from  time to  time, including
acting as an underwriter for the initial public offering of shares of the common
stock of Nellcor  on May  19, 1987. Robertson,  Stephens &  Company maintains  a
market  in  shares  of  the common  stock  of  Nellcor.  Furthermore, Robertson,
Stephens & Company has acted as financial advisor to Nellcor in connection  with
the Merger for which fees are due and payable contingent upon the closing of the
Merger.
    

   
____It  is understood that  this letter is  for the information  of the Board of
Directors of Nellcor  only and may  not be  used for any  other purpose  without
prior  written consent. Based upon and  subject to the foregoing considerations,
it is our  opinion, as  investment bankers,  that, as  of the  date hereof,  the
Exchange Ratio is fair to Nellcor and its stockholders from a financial point of
view.
    

   
                                          Very truly yours,
                                          ROBERTSON, STEPHENS & COMPANY, L.P.
                                          By: Robertson, Stephens & Company,
                                          Inc.
                                          Authorized Signatory
    

   
                                      C-2
    
<PAGE>
   
                                                                         ANNEX D
    

   
                              GOLDMAN, SACHS & CO.
    

   
                                                                    May 21, 1995
    

   
PERSONAL AND CONFIDENTIAL
    

   
Board of Directors
Nellcor Incorporated
4280 Hacienda Drive
Pleasanton, CA 94588
    

   
Gentlemen:
    

   
____You  have requested our  opinion as to the  fairness to Nellcor Incorporated
(the "Company") of the exchange ratio  (the "Exchange Ratio") of 0.88 shares  of
Common  Stock,  par value  $0.001 per  share  ("Shares"), of  the Company  to be
exchanged by the Company  for each share  of Common Stock,  par value $1.00  per
share  (the "Puritan-Bennett Shares"), of Puritan-Bennett Corporation ("Puritan-
Bennett") pursuant  to the  merger of  Puma Merger  Corporation, a  wholly-owned
subsidiary  of the Company ("Sub") with  and into Puritan-Bennett (the "Merger")
as set forth in the Agreement  and Plan of Merger dated  as of May 21, 1995,  by
and among the Company, Sub and Puritan-Bennett (the "Agreement").
    

   
____This  opinion does not address the relative merits of the Merger as compared
to any alternative business strategies that  might exist for the Company or  the
effect of any other business combination in which the Company might engage.
    

   
____Goldman,  Sachs  &  Co., as  part  of  its investment  banking  business, is
continually engaged  in the  valuation  of businesses  and their  securities  in
connection  with mergers and acquisitions, negotiated underwritings, competitive
biddings, secondary  distributions of  listed and  unlisted securities,  private
placements  and valuations for estate, corporate and other purposes. We have not
participated in  the  negotiations  leading  to the  Agreement,  and  have  been
retained  solely to provide a fairness opinion. We are familiar with the Company
having provided certain investment banking services to the Company from time  to
time,  including having  acted as managing  underwriter of a  public offering of
Shares on May  19, 1987. In  the course  of the trading  activities of  Goldman,
Sachs  & Co.  and its affiliates,  the Firm  has accumulated a  long position of
73,500 Shares against which the Firm is  short 18,039 Shares, as well as a  long
position of 217,500 Puritan-Bennett Shares.
    

   
____In  connection with this opinion, we  have reviewed, among other things, the
Agreement; Annual Reports to Stockholders and Annual Reports on Form 10-K of the
Company for  the  five  fiscal years  ended  July  3, 1994;  Annual  Reports  to
Stockholders  and Annual  Reports on Form  10-K of Puritan-Bennett  for the five
fiscal years ended January 31, 1995; certain interim reports to stockholders and
Quarterly Reports on Form  10-Q of the Company  and Puritan-Bennett and  certain
other  communications from the  Company and Puritan-Bennett  to their respective
stockholders; certain internal financial analyses and forecasts for the  Company
and   Puritan-Bennett  prepared   by  the  Company's   management;  and  certain
information (the "Synergies Information") prepared jointly by the managements of
the Company and Puritan-Bennett concerning potential cost savings and  synergies
that could result from the Merger. We also have held discussions with members of
the senior management
    

   
                                      D-1
    
<PAGE>
   
of  the  Company and  Puritan-Bennett regarding  the  past and  current business
operations, results of regulatory  examinations, financial condition and  future
prospects  of  their respective  companies. In  addition,  we have  reviewed the
reported price and trading activity  for the Shares and Puritan-Bennett  Shares,
compared  certain financial  and stock  market information  for the  Company and
Puritan-Bennett  with  similar  information  for  certain  other  companies  the
securities of which are publicly traded, reviewed the financial terms of certain
recent business combinations in the medical devices industry specifically and in
other  industries generally and performed such  other studies and analyses as we
considered appropriate.
    

   
____We have  relied  without  independent verification  upon  the  accuracy  and
completeness  of all of the  financial and other information  reviewed by us for
purposes of this opinion. We have also relied upon the management of the Company
as to  the  reasonableness and  achievability  of the  financial  and  operating
forecasts  (and the  assumptions and bases  therefore) provided to  us, and with
your consent we  have assumed that  such projections and  forecasts reflect  the
best  currently  available estimates  and judgements  of  the management  of the
Company and that such projections and forecasts will be realized in the  amounts
and  in the time periods  currently estimated by the  management of the Company.
Furthermore,  we  have  relied   upon  the  managements   of  the  Company   and
Puritan-Bennett  as to the reasonableness and  achievability of the cost savings
and synergies resulting from the  Merger reflected in the Synergies  Information
(and  the assumptions and bases therefore) provided to us, and with your consent
we have assumed that  the cost savings and  synergies resulting from the  Merger
reflect  the best currently available estimates and judgments of such respective
managements and that  such cost savings  and synergies will  be realized in  the
amounts  and in the time  periods currently estimated by  the managements of the
Company and  Puritan-Bennett.  In addition,  we  have not  made  an  independent
evaluation or appraisal of the assets and liabilities of the Company or Puritan-
Bennett  or  of  any of  their  respective  subsidiaries and  we  have  not been
furnished with any such evaluation or appraisal. We also have assumed, with your
consent, that  the Merger  will be  recorded  as a  pooling of  interests  under
generally accepted accounting principles.
    

   
____Based upon and subject to the foregoing and based upon such other matters as
we  consider relevant, it is our opinion that as of the date hereof the Exchange
Ratio pursuant to the Agreement is fair to the Company.
    

   
                                          Very truly yours,
                                          GOLDMAN, SACHS & CO.
    

   
                                      D-2
    
<PAGE>
   
                                                                         ANNEX E
    

   
                                                                    May 21, 1995
    

   
Board of Directors
Puritan-Bennett Corporation
9401 Indian Creek Parkway
Overland, Kansas 66210
    

   
Gentlemen:
    

   
____You have requested our opinion as to the fairness, from a financial point of
view, to the holders of  the shares of common stock,  par value $1.00 per  share
("Puritan-Bennett Common Stock"), of Puritan-Bennett Corporation
("Puritan-Bennett")  of the exchange ratio (the "Exchange Ratio") of 0.88 shares
of common stock, par value $0.001 per share ("Nellcor Common Stock"), of Nellcor
Incorporated ("Nellcor")  to be  exchanged  for each  share of  Puritan  Bennett
Common Stock, in the proposed merger (the "Merger") of a wholly owned subsidiary
of  Nellcor  ("Merger  Sub")  with  and  into  Puritan-Bennett  pursuant  to the
Agreement  and  Plan  of  Merger  dated  as  of  May  21,  1995  by  and   among
Puritan-Bennett, Nellcor and the Merger Sub (the "Merger Agreement").
    

   
____In  arriving  at our  opinion,  we reviewed  the  Merger Agreement  and held
discussions with certain  senior officers, directors  and other  representatives
and   advisors  of  Puritan-Bennett  and   certain  senior  officers  and  other
representatives and advisors  of Nellcor concerning  the businesses,  operations
and  prospects  of Puritan-Bennett  and  Nellcor. We  examined  certain publicly
available business  and financial  information relating  to Puritan-Bennett  and
Nellcor   as  well   as  certain   financial  forecasts   and  other   data  for
Puritan-Bennett  and  Nellcor  that  was  provided  to  us  by  the   respective
managements  of Puritan-Bennett  and Nellcor, including  information relating to
certain strategic implications of and operational benefits anticipated from  the
Merger. We reviewed the financial terms of the Merger as set forth in the Merger
Agreement in relation to, among things: current and historical market prices and
trading  volumes of Puritan-Bennett  Common Stock and  Nellcor Common Stock; the
respective companies' historical and projected earnings; and the  capitalization
and  financial condition of  Puritan-Bennett and Nellcor.  We considered, to the
extent  publicly  available,  the  financial  terms  of  certain  other  similar
transactions  recently effected that we considered  comparable to the Merger and
analyzed  certain,  financial,  stock   market  and  other  publicly   available
information  relating to the  businesses of other  companies whose operations we
considered comparable to those of Puritan-Bennett and Nellcor. We also evaluated
the potential  pro  forma  financial  impact of  the  Merger  and  the  relative
contributions  of Puritan-Bennett  and Nellcor  to selected  pro forma financial
data of the combined companies. In addition to the foregoing, we conducted  such
other  analyses and examinations  and considered such  other financial, economic
and market criteria as we deemed necessary to arrive at our opinion.
    

   
____In rendering our opinion,  we have assumed  and relied, without  independent
verification,  upon the  accuracy and  completeness of  all financial  and other
information publicly available or furnished  to or otherwise discussed with  us.
With  respect  to  financial  forecasts and  other  information  provided  to or
otherwise reviewed  by  or  discussed with  us,  we  have been  advised  by  the
respective  managements of Puritan-Bennett  and Nellcor that  such forecasts and
other  information  were  reasonably  prepared  on  bases  reflecting  the  best
currently  available estimates  and judgments  of the  respective managements of
Puritan-Bennett and Nellcor as to  the expected future financial performance  of
Puritan-Bennett  and Nellcor and  the strategic implications  of and operational
benefits anticipated from the Merger. We have also relied, with your consent and
without  independent  verification,  upon  the  assessment  by  the   respective
managements of Nellcor and Puritan-Bennett concerning certain
    
   
litiga-

                                      E-1
    
<PAGE>
   
tion  and contingencies with respect  to Nellcor. We have  also assumed that the
Merger will be treated  as a pooling-of-interests  in accordance with  generally
accepted  accounting  principles and  as a  tax-free reorganization  for federal
income tax purposes. Our opinion, as  set forth herein, relates to the  relative
values  of Puritan-Bennett and Nellcor. We are  not expressing any opinion as to
what the value  of the  Nellcor Common  Stock actually  will be  when issued  to
Puritan-Bennett  stockholders pursuant to  the Merger or the  price at which the
Nellcor Common Stock will trade  subsequent to the Merger.  We have not made  or
been  provided  with an  independent evaluation  or appraisal  of the  assets or
liabilities (contingent or otherwise) of Puritan-Bennett or Nellcor nor have  we
made  any physical inspection of the  properties or assets of Puritan-Bennett or
Nellcor. We have not been asked to  consider, and our opinion does not  address,
the  relative  merits of  the  Merger as  compared  to any  alternative business
strategies that  might exist  for Puritan-Bennett  or the  effect of  any  other
transaction  in which Puritan-Bennett  might engage. Our  opinion is necessarily
based upon  financial,  stock  market and  other  conditions  and  circumstances
existing and disclosed to us as of the date hereof.
    

   
____Smith  Barney  has been  engaged to  render  financial advisory  services to
Puritan-Bennett in connection  with the Merger  and will receive  a fee for  our
services,  a significant portion of which is contingent upon the consummation of
the Merger.  We  have  in  the past  provided  financial  advisory  services  to
Puritan-Bennett  and  have  received  compensation  for  the  rendering  of such
services. In the ordinary course of our business, we may actively trade debt and
equity securities of Puritan-Bennett and Nellcor for our own account or for  the
account  of our customers and, accordingly, may at any time hold a long or short
position in such securities. In addition,  we and our affiliates (including  The
Travelers  Inc.  and its  affiliates) may  maintain business  relationships with
Puritan-Bennett.
    

   
____Our advisory services and the  opinion expressed herein are provided  solely
for  the use of the  Board of Directors of  Puritan-Bennett in its evaluation of
the proposed  Merger  and  our opinion  is  not  intended to  be  and  does  not
constitute a recommendation to any stockholder as to how such stockholder should
vote  on the proposed merger. Our opinion may not be published or otherwise used
or referred to, nor shall any public reference to Smith Barney be made,  without
our prior written consent.
    

   
____Based  upon  and  subject to  the  foregoing, our  experience  as investment
bankers, our work as  described above and other  factors we deemed relevant,  we
are of the opinion that, as of the date hereof, the Exchange Ratio is fair, from
a financial point of view, to the holders of Puritan-Bennett Common Stock.
    

   
                                          Very truly yours,
                                          SMITH BARNEY INC.
    

   
                                      E-2
    
<PAGE>
   
                                                                         ANNEX F
    

   
____RESOLVED, that Article First of the Restated Certificate of Incorporation of
Nellcor  Incorporated be, and it  hereby is, amended to  read in its entirety as
follows:
    

   
____________"FIRST: The  name  of the  Corporation  is Nellcor  Puritan  Bennett
       Incorporated."
    

   
                                      F-1
    
<PAGE>
   
                      (THIS PAGE INTENTIONALLY LEFT BLANK)
    
<PAGE>
   
                                    PART II
                            INFORMATION NOT REQUIRED
                               IN THE PROSPECTUS
    

   
ITEM 20. INDEMNIFICATION OF DIRECTORS AND OFFICERS
    
   
____Reference  is made to Section 145 ("Section 145") of the General Corporation
Law of the State of Delaware (the "DGCL") which provides for indemnification  of
directors and officers in certain circumstances.
    

   
____Nellcor's  Restated Certificate of Incorporation provides that a director of
Nellcor will  not  be personally  liable  to  Nellcor or  its  stockholders  for
monetary  damages for breach of  fiduciary duty as a  director of Nellcor except
for liability (i) for any breach of  such director's duty of loyalty to  Nellcor
or  its stockholders,  (ii) for  acts or  omissions not  in good  faith or which
involve intentional misconduct or  a knowing violation of  the law, (iii)  under
Section  174  of  the DGCL  (unlawful  payment  of dividends)  or  (iv)  for any
transaction from which such director derived an improper personal benefit.
    

   
____Nellcor is empowered by Section 145  of the DGCL, subject to the  procedures
and  limitations  stated  therein,  to  indemnify  any  person  against expenses
(including attorney's fees),  judgments, fines  and amounts  paid in  settlement
actually  and  reasonably  incurred  by  such  person  in  the  defense  of  any
threatened, pending or completed action, suit or proceeding in which such person
is made a  party by reason  of his  or her being  or having been  a director  or
officer  of Nellcor. The  statute provides that  indemnification pursuant to its
provisions is not exclusive of other rights of indemnification to which a person
may  be  entitled  under   any  bylaw,  agreement,   vote  of  stockholders   or
disinterested directors, or otherwise.
    

   
____Nellcor's  By-Laws provide that  Nellcor shall indemnify  its directors, and
may indemnify its  officers, to the  full extent permitted  by law. Nellcor  has
entered  into agreements with each of  its directors and executive officers, and
with certain  other  employees,  providing that  Nellcor  will  indemnify  those
persons  to the full extent permitted by law against claims arising out of their
actions as agents of Nellcor and will advance expenses of defending against such
claims. Nellcor may  enter into  similar indemnification  agreements with  other
officers, employees or directors in the future.
    

   
____Nellcor  presently  maintains  directors  and  officers  liability insurance
coverage.
    

   
ITEM 21. EXHIBITS AND FINANCIAL STATEMENT SCHEDULES.
    

   
____(a)_The following exhibits are filed herewith unless otherwise indicated:
    

   
<TABLE>
<CAPTION>
  EXHIBIT
  NUMBER
- -----------
<C>          <S>
       2.1   Agreement and Plan of Merger Among Nellcor Incorporated, Puma Merger Corporation, a wholly-owned
             subsidiary of Nellcor Incorporated, and Puritan-Bennett Corporation, dated May 21, 1995 (included
             as Annex A to the Proxy Statement/Prospectus filed as part of this Registration Statement).
       2.2   Amendment No. 1 to Agreement and Plan of Merger, dated as of June 30, 1995 (included as Annex B
             to the Proxy Statement/Prospectus filed as part of this Registration Statement).
       4.1   Restated Certificate of Incorporation of Nellcor Incorporated (incorporated by reference to
             Exhibit 3.1 to the Registrant's Annual Report on Form 10-K for the year ended July 7, 1991).
       4.2   Certificate of Determination of Preferences of Series A Junior Participating Preferred Stock of
             Nellcor Incorporated (incorporated by reference to Exhibit 3.2 to the Registrant's Annual Report
             on Form 10-K for the year ended July 7, 1991).
       4.3   Bylaws of Nellcor Incorporated, as amended (incorporated by reference to Exhibit 3.3 of the
             Registrant's Annual Report on Form 10-K for the year ended July 3, 1994).
</TABLE>
    

                                      II-1
<PAGE>
   
<TABLE>
<CAPTION>
  EXHIBIT
  NUMBER
- -----------
       4.4   Rights Agreement, dated as of September 1, 1992, between Nellcor Incorporated and The First
             National Bank of Boston, as Rights Agent (incorporated by reference to Exhibit 2.1 of Amendment
             No. 1 to the Registrant's Registration Statement on Form 8-A filed with the Commission on July
             13, 1995).
<C>          <S>
       5.1   Opinion of Morrison & Foerster as to legality of issuance of Nellcor Common Stock.
       8.1   Opinion of Morrison & Foerster as to certain U.S. tax issues.
       8.2   Opinion of Blackwell Sanders Matheny Weary & Lombardi L.C. as to certain U.S. tax issues.
      23.1   Consent of Price Waterhouse LLP.
      23.2   Consent of Ernst & Young LLP.
      23.3   Consent of Morrison & Foerster (included in Exhibit 5.1).
      23.4   Consent of Morrison & Foerster (included in Exhibit 8.1).
      23.5   Consent of Blackwell Sanders Matheny Weary & Lombardi L.C. (included in Exhibit 8.2).
      23.6   Consent of Burton A. Dole, Jr.
      23.7   Consent of Thomas A. McDonnell.
      24.1   Powers of Attorney (included on page II-4).
      99.1   Form of Proxy Card for Nellcor Incorporated.
      99.2   Form of Proxy Card for Puritan-Bennett Corporation.
</TABLE>
    

   
____(b)_Financial Statement Schedules
    

   
Schedule I__--_ Marketable Securities  --  Other  Investments  (incorporated  by
                reference  to page S-3 of the Registrant's Annual Report on Form
                10-K for the year ended July 3, 1994).
    

   
Schedule II_--_ Amounts  Receivable  from  Related  Parties  and   Underwriters,
                Promoters,    and   Employees   other   than   Related   Parties
                (incorporated by  reference  to  page S-4  of  the  Registrant's
                Annual Report on Form 10-K for the year ended July 3, 1994).
    

   
____Other  schedules are omitted  because the absence  of conditions under which
they  are  required  or  because  the  required  information  is  given  in  the
consolidated financial statements or notes thereto.
    

   
ITEM 22. UNDERTAKINGS
    
   
____The undersigned registrant hereby undertakes as follows:
    

   
    ____(a)_That, for purposes of determining any liability under the Securities
    Act  of  1933, each  filing of  the registrant's  annual report  pursuant to
    Section 13(a) or Section 15(d) of  the Securities Exchange Act of 1934  that
    is  incorporated by reference in the  registration statement shall be deemed
    to be  a  new registration  statement  relating to  the  securities  offered
    therein, and the offering of such securities at that time shall be deemed to
    be the initial bona fide offering thereof;
    

   
    ____(b)   (1)__That  prior  to  any  public  reoffering  of  the  securities
    registered hereunder through  use of a  prospectus which is  a part of  this
    registration  statement,  by any  person or  party  who is  deemed to  be an
    underwriter within the meaning  of Rule 145(c),  the issuer undertakes  that
    such  reoffering prospectus will  contain the information  called for by the
    applicable registration form with respect to reofferings by persons who  may
    be  deemed underwriters,  in addition to  the information called  for by the
    other Items of the applicable form;
    

   
    ____(2)_That every prospectus (i)  that is filed  pursuant to paragraph  (1)
    immediately  preceding, or  (ii) that purports  to meet  the requirements of
    section 10(a)(3) of the  Securities Act of 1933,  and is used in  connection
    with an offering of securities subject to Rule 415, will be filed as part of
    an  amendment to the registration statement and  will not be used until such
    amendment is effective,
    

                                      II-2
<PAGE>
   
    and that, for purposes of determining any liability under the Securities Act
    of 1933, each  such post-effective  amendment shall be  deemed to  be a  new
    registration  statement relating to the  securities offered therein, and the
    offering of such securities at that time  shall be deemed to be the  initial
    bona fide offering thereof;
    

   
    ____(c)_Insofar   as  indemnification  for  liabilities  arising  under  the
    Securities  Act  of  1933  may  be  permitted  to  directors,  officers  and
    controlling  persons of the registrant pursuant to the foregoing provisions,
    or otherwise, the  registrant has been  advised that in  the opinion of  the
    Securities  and Exchange  Commission such indemnification  is against public
    policy as  expressed  in the  Securities  Act  of 1933  and  is,  therefore,
    unenforceable.  In the event  that a claim  for indemnification against such
    liabilities (other than the payment  by the registrant of expenses  incurred
    or  paid by a director,  officer or controlling person  of the registrant in
    the successful defense  of any action,  suit or proceeding)  is asserted  by
    such  director,  officer,  or  controlling  person  in  connection  with the
    securities being registered, the registrant  will, unless in the opinion  of
    its  counsel the matter has been settled by controlling precedent, submit to
    a  court  of   appropriate  jurisdiction  the   question  of  whether   such
    indemnification  by  it  is  against  public  policy  as  expressed  in  the
    Securities Act of  1933 and will  be governed by  the final adjudication  of
    such issue;
    

   
    ____(d)_To  respond  to requests  for  information that  is  incorporated by
    reference into the prospectus pursuant to Items  4, 10(b), 11 or 13 of  this
    Form  S-4, within one business  day of receipt of  such request, and to send
    the incorporated  documents by  first  class mail  or other  equally  prompt
    means.  This includes information contained in documents filed subsequent to
    the effective  date  of  the  Registration Statement  through  the  date  of
    responding to the request; and
    

   
    ____(e)_To  supply by  means of  a post-effective  amendment all information
    concerning a transaction, and the  company being acquired involved  therein,
    that  was not the subject of and included in the Registration Statement when
    it became effective.
    

                                      II-3
<PAGE>
   
                                   SIGNATURES
    

   
____Pursuant to the requirements of the  Securities Act of 1933, the  Registrant
has  duly caused this Amendment No. 1  to Registration Statement to be signed on
its behalf  by  the undersigned,  thereunto  duly  authorized, in  the  City  of
Pleasanton, State of California, on the 21st day of July, 1995.
    

                                          NELLCOR INCORPORATED

   
                                          By_____/s/ C. RAYMOND LARKIN, JR._____

                                          --------------------------------------
                                                  C. Raymond Larkin, Jr.
                                                   PRESIDENT AND CHIEF
                                                    EXECUTIVE OFFICER
    

   
____Pursuant  to the requirements of the  Securities Act of 1933, this Amendment
No. 1 to Registration Statement has  been signed below by the following  persons
in the capacities indicated on the 21st day of July, 1995.
    

   
<TABLE>
<CAPTION>
                      SIGNATURE                                                 TITLE
- ------------------------------------------------------  ------------------------------------------------------

<C>                                                     <S>
              /s/ C. RAYMOND LARKIN, JR.
     -------------------------------------------        President and Chief Executive Officer and Director
                C. Raymond Larkin, Jr.                   (principal executive officer)

                          *
     -------------------------------------------        Executive Vice President, Chief Financial Officer
                  Michael P. Downey                      (principal financial and accounting officer)

                          *
     -------------------------------------------        Director
                Robert J. Glaser, M.D.

                          *
     -------------------------------------------        Director
                 Frederick M. Grafton

                          *
     -------------------------------------------        Director
                  Donald L. Hammond

                          *
     -------------------------------------------        Director
                  Walter J. McNerney

                          *
     -------------------------------------------        Director
               Edwin E. van Bronkhorst

                *By/s/ LAUREEN DEBUONO
       ---------------------------------------
                   Laureen DeBuono
                   ATTORNEY-IN-FACT
</TABLE>
    

                                      II-4

<PAGE>
                                                                     EXHIBIT 5.1

July 20, 1995

Nellcor Incorporated
4280 Hacienda Drive
Pleasanton, CA 94588

       Re:  Nellcor Incorporated:
            11,860,150 Shares of Common Stock

Ladies and Gentlemen:

    At  your request,  we have examined  the Registration Statement  on Form S-4
filed by you with the  Securities and Exchange Commission  on July 20, 1995,  in
connection  with the registration under the  Securities Act of 1933, as amended,
of 11,860,150 shares of  your Common Stock, par  value of $0.001 (the  "Stock").
The  Stock  is  to  be  issued to  the  former  stockholders  of Puritan-Bennett
Corporation, a  Delaware corporation  ("P-B"),  pursuant to  the terms  of  that
certain  Agreement and Plan of Merger, dated as  of May 21, 1995, as amended, by
and between  you,  Puma Merger  Corporation,  a Delaware  corporation  and  your
wholly-owned subsidiary, and P-B.

    In  connection with this opinion, we  have examined all proceedings taken by
you relating to the issuance and sale of up to 11,860,150 shares of the Stock.

    It is our opinion that the up to 11,860,150 shares of the Stock being issued
and sold  by  you, when  issued  and  sold in  the  manner referred  to  in  the
Registration  Statement, will  be legally  and validly  issued, fully  paid, and
nonassessable.

    We consent to  the use of  this opinion  as an exhibit  to the  Registration
Statement  and  further consent  to  all references  to  us in  the Registration
Statement, the Proxy  Statement/Prospectus constituting a  part thereof and  any
amendments thereto.

                                          Very truly yours,

   
                                          /s/ MORRISON & FOERSTER
    

                                          --------------------------------------
   
                                          Morrison & Foerster
    

<PAGE>
                                                                     EXHIBIT 8.1

July 18, 1995

Nellcor Incorporated
4280 Hacienda Drive
Pleasanton, CA 94588

    RE: NELLCOR INCORPORATED PROXY STATEMENT
       AND REGISTRATION STATEMENT ON FORM S-4

Ladies and Gentlemen:

    We  have acted  as counsel to  Nellcor Incorporated,  a Delaware corporation
("Nellcor")  and  Puma  Merger  Corporation,   a  Delaware  corporation  and   a
wholly-owned  subsidiary of Nellcor ("Sub") in connection with the Agreement and
Plan of Merger, dated as of May  21, 1995 (the "Merger Agreement"), as  amended,
by   and  among  Nellcor,  Sub   and  Puritan-Bennett  Corporation,  a  Delaware
corporation ("P-B").

    Pursuant to the  Merger Agreement,  Sub will merge  into and  with P-B  (the
"Merger").  As a result of the Merger, P-B will become a wholly-owned subsidiary
of Nellcor and  the former shareholders  of P-B will  receive shares of  Nellcor
common stock, all on the terms set forth in the Merger Agreement.

    The  Merger Agreement and certain proposed transactions incident thereto are
described in the Registration  Statement on Form S-4  filed by Nellcor with  the
Securities  and Exchange Commission (the "Registration Statement"). This opinion
is being rendered pursuant to the requirements  of Item 21(a) of Form S-4  under
the Securities Act of 1933, as amended.

    In  connection with this opinion, we have examined and are familiar with the
Merger Agreement, the Registration Statement, and such other presently  existing
documents,  records  and  matters  of  law  as  we  have  deemed  necessary  and
appropriate in connection with rendering this opinion.

    In rendering this opinion, we assume the following:

    1.  The authenticity of original  documents submitted to us, the  conformity
to original documents of all documents submitted to us as photostatic copies and
the  authenticity of the  originals of such  copies, and the  genuineness of all
signatures and the due execution and delivery of all documents.

    2.  The truth  and accuracy of  the representations, warranties,  statements
and  facts made or  to be made  by Nellcor, Sub  and P-B in  connection with the
Merger, including those representations set forth in the Merger Agreement and in
certificates of representations provided to us by Nellcor and P-B.

    Based upon and  subject to the  foregoing, the discussion  contained in  the
prospectus  included as  part of  the Registration  Statement (the "Prospectus")
under the  caption  "Certain Federal  Income  Tax Consequences,"  expresses  our
opinion  as to  the material  Federal income tax  consequences if  the Merger is
effected according to the terms of the Merger Agreement. Because this opinion is
being delivered prior to the Effective Time of the Merger, it must be considered
prospective and dependent upon future events.  In addition, you should be  aware
that  the discussion under the caption "Certain Federal Income Tax Consequences"
in the Prospectus represents our conclusions  as to the application of  existing
law  to the instant transactions and may not be applicable to certain classes of
P-B stockholders, including securities dealers, foreign persons and persons  who
acquired  their  P-B Common  Stock pursuant  to the  exercise of  employee stock
options or rights or otherwise as  compensation. There can be no assurance  that
changes in the law will not take place which could affect the Federal income tax
consequences  of the Merger or  that contrary positions may  not be taken by the
Internal Revenue Service.
<PAGE>
Nellcor Incorporated
July 18, 1995
Page Two

    This opinion  is furnished  to you  solely for  use in  connection with  the
Registration  Statement. We hereby consent  to the filing of  this opinion as an
exhibit to the Registration Statement. We also consent to the references to  our
firm  name wherever appearing in the  Registration Statement with respect to the
discussion of the Federal income tax  consequences of the Merger, including  the
Prospectus constituting a part thereof, and any amendment thereto.

                                          Very truly yours,

   
                                          /s/ MORRISON & FOERSTER
    

                                          --------------------------------------
   
                                          Morrison & Foerster
    

<PAGE>
                                                                     EXHIBIT 8.2

July 18, 1995

Puritan-Bennett Corporation
9401 Indian Creek Parkway
Building 40
P.O. Box 25905
Overland Park, KS 66225-5905

Ladies and Gentlemen:

    We  have  acted  as  counsel  to  Puritan-Bennett  Corporation,  a  Delaware
corporation ("P-B"), in connection with a proposed transaction (the "Merger") in
which  P-B  will  become  a  wholly-owned  subsidiary  of  Nellcor  Incorporated
("Nellcor")  pursuant to  an Agreement and  Plan of  Merger dated as  of May 21,
1995,  as  amended  by  Amendment  No.  1  dated  June  30,  1995  (the  "Merger
Agreement"),  under  which  Puma  Merger  Corporation  ("Sub"),  a  wholly-owned
subsidiary of Nellcor, will be merged into P-B. The proposed transaction and the
Merger Agreement are more fully described in the Registration Statement on  Form
S-4  (the "Registration Statement")  to be filed by  Nellcor with the Securities
and Exchange Commission  and the  joint proxy  statement/prospectus (the  "Proxy
Statement/Prospectus")  included  in  such  Registration  Statement. Capitalized
terms not otherwise  defined herein have  the meanings ascribed  to them in  the
Proxy Statement/Prospectus.

    Based  upon  our  review  of  the  Proxy  Statement/Prospectus,  the  Merger
Agreement and such other documents as we have deemed necessary and upon  certain
representations made to us by Nellcor and P-B, assuming the Merger and all other
events  occur as  contemplated in the  Proxy Statement/  Prospectus and assuming
such representations remain  true as of  the Effective Time,  it is our  opinion
that  under the  Internal Revenue  Code of  1986, as  amended (the  "Code"), the
legislative history  with respect  thereto,  rules and  regulations  promulgated
thereunder,  published  rulings  of  the  Internal  Revenue  Service  and  court
decisions, all as in effect  and existing on the date  hereof, and all of  which
are subject to change at any time, possibly on a retroactive basis:
<PAGE>
Puritan-Bennett Corporation
July 18, 1995
Page 2

        (i)  the Merger will  constitute a reorganization  within the meaning of
    Section 368(a) of the Code, and Nellcor, Sub and P-B will each be a party to
    that reorganization within the meaning of Section 368(b) of the Code;

        (ii) no gain or loss will be recognized by Nellcor or P-B as a result of
    the Merger;

        (iii) no gain or loss will be recognized by the stockholders of P-B upon
    the conversion of their P-B Common Stock into shares of Nellcor Common Stock
    pursuant to the Merger except with respect to cash, if any, received in lieu
    of fractional shares of Nellcor Common Stock;

        (iv) a  stockholder of  P-B will  recognize gain  or loss  equal to  the
    difference  between the cash received in lieu of a fractional share interest
    of Nellcor Common Stock and such  stockholder's tax basis in the  fractional
    share for which cash is received;

        (v)  no gain or loss will be  recognized by the existing stockholders of
    Nellcor as a result of the Merger;

        (vi) the  aggregate tax  basis of  the shares  of Nellcor  Common  Stock
    received  in exchange for shares of P-B  Common Stock pursuant to the Merger
    (including fractional shares for which cash is received) will be the same as
    the aggregate tax basis  for such shares of  P-B Common Stock, decreased  by
    the  amount of any tax basis allocable to the fractional share interests for
    which cash is received; and

        (vii) the holding period for shares of Nellcor Common Stock received  in
    exchange  for shares of P-B Common Stock pursuant to the Merger will include
    the period that such  shares of P-B  Common Stock were  held by the  holder,
    provided  such shares of P-B Common Stock were held as capital assets by the
    holder at the Effective Time.

    This opinion  is limited  to the  matters stated  herein and  no opinion  is
implied or may be inferred beyond the matters expressly stated herein.
<PAGE>
Puritan-Bennett Corporation
July 18, 1995
Page 3

    We hereby consent to the filing of this opinion as an Exhibit to the
Registration Statement and to all references to our firm included in or made a
part of the Registration Statement. In giving this consent, we do not thereby
admit that we are in the category of persons whose consent is required under
Section 7 of the Securities Act of 1933, as amended, or the rules and
regulations of the Securities and Exchange Commission thereunder.

                                          Very truly yours,

   
                                          /s/ BLACKWELL SANDERS MATHENY
                                           WEARY & LOMBARDI L.C.
    

                                          --------------------------------------
   
                                          Blackwell Sanders Matheny
                                          Weary & Lombardi L.C.
    

<PAGE>
                                                                    EXHIBIT 23.1

                       CONSENT OF INDEPENDENT ACCOUNTANTS

   
    We  hereby  consent to  the incorporation  by reference  in the  Joint Proxy
Statement/Prospectus constituting part of this  Amendment No. 1 to  Registration
Statement on Form S-4 of Nellcor Incorporated and Puritan-Bennett Corporation of
our   report  dated  July  27,  1994,  which  appears  on  page  35  of  Nellcor
Incorporated's 1994  Annual Report  to Stockholders,  which is  incorporated  by
reference  in its Annual Report on Form 10-K for the year ended July 3, 1994. We
also consent to the  incorporation by reference of  our report on the  Financial
Statement  Schedules, which appears  on page S-1  of such Annual  Report on Form
10-K. We also consent to the reference to us under the heading "Experts" in such
Joint Proxy Statement/Prospectus.
    

   
                                          /s/ PRICE WATERHOUSE LLP
    

                                          --------------------------------------
   
                                          Price Waterhouse LLP
    

San Francisco, California
   
July 20, 1995
    

<PAGE>
                                                                    EXHIBIT 23.2

                        CONSENT OF INDEPENDENT AUDITORS

   
    We  consent to the reference to our  firm under the caption "Experts" in the
Joint Proxy  Statement/Prospectus of  Nellcor Incorporated  and  Puritan-Bennett
Corporation  which is made part of Amendment No. 1 to the Registration Statement
on Form S-4 of Nellcor Incorporated for the registration of shares of its common
stock to be issued  to the stockholders of  Puritan-Bennett Corporation, and  to
the  incorporation by reference therein of our reports dated March 6, 1995, with
respect to the consolidated financial statements of Puritan-Bennett  Corporation
and  subsidiaries incorporated by reference in its Annual Report (Form 10-K) for
the year ended January 31, 1995, and April 25, 1995, with respect to the related
financial statement schedule  included therein,  filed with  the Securities  and
Exchange Commission.
    

   
                                          /s/ ERNST & YOUNG LLP
    

                                          --------------------------------------
   
                                          Ernst & Young LLP
    

Kansas City, Missouri
July 19, 1995

<PAGE>
                                                                    EXHIBIT 23.6

                     CONSENT OF PERSON TO BECOME A DIRECTOR

    I  hereby consent to being named in  this Registration Statement as a person
who may become a director of Nellcor Incorporated.

   
                                          /s/ BURTON A. DOLE, JR.
    

                                          --------------------------------------
                                          Burton A. Dole, Jr.

Dated: July 10, 1995

<PAGE>
                                                                    EXHIBIT 23.7

                      CONSENT OF PERSON TO BECOME DIRECTOR

    I  hereby consent to being named in  this Registration Statement as a person
who may become a director of Nellcor Incorporated.

   
                                          /s/ THOMAS A. MCDONNELL
    

                                          --------------------------------------
                                          Thomas A. McDonnell

Dated: July 20, 1995

<PAGE>
PROXY                                                               EXHIBIT 99.1

                              NELLCOR INCORPORATED
              PROXY SOLICITED ON BEHALF OF THE BOARD OF DIRECTORS
           FOR THE SPECIAL MEETING OF STOCKHOLDERS -- AUGUST 24, 1995

    C. Raymond Larkin, Jr. and Laureen DeBuono, or either of them, each with the
power  of substitution  and revocation, are  hereby authorized  to represent the
undersigned, with all powers which  the undersigned would possess if  personally
present,  to vote the Common Stock of  the undersigned at the Special Meeting of
Stockholders of  NELLCOR  INCORPORATED  ("Nellcor"), to  be  held  at  Nellcor's
offices  at 4280 Hacienda  Drive, Pleasanton, California 94588  at 10:00 a.m. on
Thursday, August 24, 1995,  or any adjournment or  postponement thereof, as  set
forth on the reverse side.

    THE  BOARD OF  DIRECTORS RECOMMENDS  A VOTE  "FOR" APPROVAL  OF EACH  OF THE
PROPOSALS LISTED ON THE REVERSE SIDE.

    THIS PROXY WILL BE VOTED AS SPECIFIED OR, IF NO CHOICE IS SPECIFIED, WILL BE
VOTED "FOR" APPROVAL OF EACH OF THE PROPOSALS LISTED ON THE REVERSE SIDE.

                   CONTINUED AND TO BE SIGNED ON REVERSE SIDE
                                SEE REVERSE SIDE

    /X/ Please mark votes as in this example.

    THIS PROXY ALSO GRANTS TO THE PROXYHOLDERS THE AUTHORITY TO VOTE THE  SHARES
IN THEIR DISCRETION ON ANY OTHER MATTERS AS MAY PROPERLY COME BEFORE THE SPECIAL
MEETING.

<TABLE>
<S>        <C>
1.         To approve the issuance of Nellcor
           Common Stock in connection with the
           Agreement and Plan of Merger, dated as
           of May 21, 1995, as amended, among
           Nellcor, Puma Merger Corporation, a
           wholly-owned subsidiary of Nellcor
           ("Sub"), and Puritan-Bennett Corporation
           ("P-B"), pursuant to which Sub will be
           merged with and into P-B, and P-B will
           become a wholly-owned subsidiary of
           Nellcor.
           FOR  / / AGAINST  / / ABSTAIN  / /
2.         To approve an amendment to the Restated
           Certificate of Incorporation of Nellcor
           to change Nellcor's corporate name to
           Nellcor Puritan Bennett Incorporated.
           FOR  / / AGAINST  / / ABSTAIN  / /
3.         To approve the adoption of Nellcor's
           1995 Merger Stock Incentive Plan.
           FOR  / / AGAINST  / / ABSTAIN  / /
4.         To approve the adoption of an amendment
           to Nellcor's 1994 Equity Incentive Plan
           to increase the number of shares of
           Nellcor Common Stock authorized for
           issuance under the Plan from 1,500,000
           shares to 2,500,000 shares.
           FOR  / / AGAINST  / / ABSTAIN  / /
</TABLE>

    PLEASE  MARK,  SIGN, DATE  AND  RETURN THIS  PROXY  CARD PROMPTLY  USING THE
ENCLOSED POSTAGE PREPAID ENVELOPE.

SIGNATURE: ___________________________________________  DATE ___________________

SIGNATURE: ___________________________________________  DATE ___________________

    Please  sign   exactly   as   signer's  name   appears   above.   Executors,
administrators,  trustees, guardians, attorneys-in-fact,  etc. should give their
full titles. If  signer is a  corporation, please give  full corporate name  and
have  a duly  authorized officer sign,  stating title. If  a partnership, please
sign in partnership  name by authorized  person. If stock  is registered in  two
names, both should sign.

<PAGE>
                                                                    EXHIBIT 99.2

<TABLE>
<S>                                                 <C>
PURITAN-BENNETT CORPORATION                         THIS    PROXY   IS   SOLICITED   ON   BEHALF   OF   THE   BOARD   OF   DIRECTORS
9401 INDIAN CREEK PARKWAY                           The undersigned  hereby appoints  Burton A.  Dole, Jr.  and Daniel  C. Weary  as
OVERLAND PARK, KANSAS                               Proxies,  each with the  power to appoint his  substitute, and hereby authorizes
66210                            PROXY              them to represent and  to vote, as  designated below, all  the shares of  common
- --------------------------                          stock of Puritan-Bennett Corporation that the undersigned is entitled to vote at
                                                    the  special meeting of the  stockholders to be held on  August 24, 1995, or any
                                                    adjournment or postponement thereof. Receipt of the Notice of Meeting and  Joint
                                                    Proxy  Statement/Prospectus is hereby acknowledged. This proxy revokes all prior
                                                    proxies given by the undersigned.
</TABLE>

THE BOARD  OF DIRECTORS  RECOMMENDS A  VOTE  "FOR" THE  ADOPTION OF  THE  MERGER
AGREEMENT (AS DEFINED BELOW).

1.   Proposal to  adopt the Agreement  and Plan of  Merger, dated as  of May 21,
    1995, as amended (the "Merger Agreement"), by and among Nellcor Incorporated
    ("Nellcor"), Puma Merger Corporation,  a wholly-owned subsidiary of  Nellcor
    ("Sub"), and Puritan-Bennett Corporation ("P-B"), pursuant to which Sub will
    be  merged with and into P-B, and  P-B will become a wholly-owned subsidiary
    of Nellcor.

                FOR  / /        AGAINST  / /        ABSTAIN  / /

2.  IN  THEIR DISCRETION, THE  PROXIES ARE  AUTHORIZED TO VOTE  UPON SUCH  OTHER
    BUSINESS AS MAY PROPERLY COME BEFORE THE MEETING AND ALL MATTERS INCIDENT TO
    THE CONDUCT OF THE MEETING.

THIS PROXY WHEN PROPERLY EXECUTED WILL BE VOTED IN THE MANNER DIRECTED HEREIN BY
THE  UNDERSIGNED STOCKHOLDER. IF NO DIRECTION IS  MADE, THIS PROXY WILL BE VOTED
FOR THE PROPOSAL TO ADOPT THE MERGER AGREEMENT.
                                         Dated _________________________________
                                         _______________________________________
                                         Signature
                                         _______________________________________
                                         Signature if held jointly

                                         Please sign exactly as name appears  to
                                         the left. When shares are held by joint
                                         tenants, both should sign. When signing
                                         as an attorney, executor,
                                         administrator,   trustee  or  guardian,
                                         please give full  title as  such. If  a
                                         corporation,   please   sign   in  full
                                         corporate name  by President  or  other
                                         authorized  officer. If  a partnership,
                                         please sign in  partnership name by  an
                                         authorized person.

                                         Please  Mark, Sign, Date and Return The
                                         Proxy Card Promptly Using The  Enclosed
                                         Postage Prepaid Envelope.


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