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EXHIBIT C
JOINT FILING AGREEMENT
The undersigned hereby agree that the statement on Schedule 13D with
respect to the shares of Common Stock of Detection Systems, Inc. dated December
21, 2000 is and any amendments thereto signed by each of the undersigned shall
be, filed on behalf of each of them pursuant to and in accordance with the
provisions of Rule 13d-1(f) under the Securities and Exchange Act of 1934.
Dated: December 21, 2000
ULTRAK, INC.
By: /s/ Chris Sharng
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Name: Chris Sharng
Title: Secretary
SECURITY WARRANTY, INC.
By: /s/ Chris Sharng
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Name: Chris Sharng
Title: Secretary