<PAGE>
EXHIBIT 4.1
OPNET
Optimum Network Performance
OPNET Technologies, Inc.
NUMBER SHARES
OT
INCORPORATED UNDER THE LAWS OF THE STATE OF DELAWARE
COMMON STOCK CUSIP 683757 10 8
SEE REVERSE FOR CERTAIN DEFINITIONS
This Certifies that
is the owner of
FULLY PAID AND NONASSESSABLE SHARES OF COMMON STOCK, PAR VALUE $.001 PER SHARE,
OF OPNET Technologies, Inc.
(the "Corporation"), a Delaware corporation. The Shares represented by this
certificate are transferable only on the stock transfer books of the Corporation
by the holder of record hereof, or by his duly authorized attorney or legal
representative, upon the surrender of this certificate properly endorsed. This
certificate and the Shares represented hereby are subject to the laws of the
State of Delaware and all the provisions of the Certificate of Incorporation and
By-Laws of the Corporation, each as now in effect or hereafter amended, to all
of which provisions the holder by acceptance hereof assents. This certificate is
not valid until countersigned and registered by the Corporation's transfer agent
and registrar.
IN WITNESS WHEREOF, the Corporation has caused this certificate to be
executed by the facsimile signature of its duly authorized officers and has
caused a facsimile of its corporate seal to be hereunto affixed.
Countersigned and Registered:
AMERICAN STOCK TRANSFER & TRUST COMPANY
Transfer Agent
and Registrar.
By
--------------------------------------------
Authorized Signature
Dated: OPNET Technologies, Inc.
CORPORATE
SEAL
0000
DELAWARE
*
/s/ Marc A. Cohen /s/ Alain Cohen
------------------------------------- -------------------------------
Secretary and Chief Executive Officer President
<PAGE>
OPNET Technologies, Inc.
The Corporation has authority to issue stock of more than one class. The
Corporation will furnish without charge to each stockholder who so requests the
powers, designations, preferences and relative, participating, optional or other
special rights of each class of stock or series thereof of the Corporation, and
the qualifications, limitations, or restrictions of such preferences and/or
rights. Such request may be made to the Corporation or the transfer agent.
The following abbreviations, when used in the inscription on the face of
this certificate, shall be construed as though they were written out in full
according to applicable laws or regulations:
TEN COM - as tenants in common UNIF GIFT MIN ACT-.........Custodian...........
(Cust) (Minor)
TEN ENT - as tenants by the entireties under Uniform Gifts to Minors
JT TEN - as joint tenants with right Act..........................
of survivorship and not as (State)
tenants in common
Additional abbreviations may also be used though not in the above list.
For value received, ______________ hereby sell, assign and transfer unto
PLEASE INSERT SOCIAL SECURITY OR OTHER
IDENTIFYING NUMBER OF ASSIGNEE
--------------------------------------------------
| |
| |
--------------------------------------------------
________________________________________________________________________________
(PLEASE PRINT OR TYPEWRITE NAME AND ADDRESS INCLUDING ZIP CODE OF ASSIGNEE)
________________________________________________________________________________
________________________________________________________________________________
__________________________________________________________________________shares
of the Common Stock represented by the within Certificate, and do hereby
irrevocably constitute and appoint
________________________________________________________________________Attorney
to transfer the said shares on the books of the within-named Corporation with
full power of substitution in the premises.
Dated ____________________
--------------------------------------------------------
NOTICE: The signature to this assignment must correspond with
the name as written upon the face of the Certificate, in
every particular, without alteration or englargement or
any change whatever.
Signature(s) Guaranteed:
By _____________________________________________________________________________
THE SIGNATURE(S) SHOULD BE GUARANTEED BY AN ELIGIBLE GUARANTOR INSTITUTION
(BANKS, STOCKBROKERS, SAVINGS AND LOAN ASSOCIATIONS AND CREDIT UNIONS WITH
MEMBERSHIP IN AN APPROVED SIGNATURE GUARANTEE MEDALLION PROGRAM), PURSUANT TO
S.E.C. RULE 17Ad-15.
