Detection Systems Inc Watch

from SC 13D 1 page <page> Exhibits Exhibit No. Description 1 Joint Filing Agreement Dated as of December 20, 2000, by and Between Parent and the Purchaser. <page> Exhibit No. 1 Joint Filing Agreement in Accordance With Rule 13d-1(k) Under the Securities Exchange Act of 1934, as Amended, the Persons Named Below Each Hereby Agrees That the Schedule 13d Filed Herewith and Any Amendments Thereto Relating to the Acquisition of Shares of Common Stock of Detection Systems, Inc. Is Filed Jointly on Behalf of Such Person. Dated: December 20, 2000 Robert Bosch Gmbh By: /S/ Georg Hanen Name: Georg Hanen Title: Senior Vice President By: /S/ Dr. Heiko Carrie Name: Dr. Heiko Carrie Title: Senior Legal Counsel Bosch Security Systems Corporation By: /S/ Gary Saunders Name: Gary Saunders Title: President 13

from SC 14D9 ~50 pages Agreement and Plan of Merger

from S-2/A ~50 pages Underwriting Agreement

from 10-K405 1 page Exhibit 1 -- Price Range of Common Stock the Quarterly High and Low Bid of the Company's Common Stock During the Past Three Years. (In Dollars) <table> Fiscal Fiscal Fiscal Fiscal 1996 * 1995 1994 1993 High Low High Low High Low High Low --- <s> <c> <c> <c> <c> <c> <c> <c> <c> First Quarter Ended June 30 7-1/2 6-1/2 10-1/2 6 8-1/4 5-3/4 6-1/4 5 Second Quarter Ended Sept 30 9-1/2 6-1/8 6-3/4 5-3/4 6-1/8 5 Third Quarter Ended Dec 31 9-3/8 5-1/2 12 6-1/8 5-5/8 4-3/4 Fourth Quarter 8 5-3/4 13 9 9-1/2 5-1/4 * Through May 11, 1995 </Table>

from DEF 14A ~5 pages Underwriting agreement