================================================================================ SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Amendment No. 4 to Schedule TO Tender Offer Statement under Section 14(d)(1) or 13(e)(1) of the Securities Exchange Act of 1934 Microtest, Inc. (Name of Subject Company) Phoenix Acquisition Corp. Danaher Corporation (Name of Filing Person-Offeror) Common Stock, Par Value $0.001 Per Share Preferred Share Purchase Rights (Title of Class of Securities) 594941106 (CUSIP Number of Class of Securities) Patrick W. Allender Executive Vice President, Chief Financial Officer and Secretary 2099 Pennsylvania Avenue, NW, 12th Floor Washington, D.C. 20006-1813 Telephone: (202) 828-0850 (Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications on Behalf of Filing Persons) Copy to: Mark A. Dewire, Esq. Wilmer, Cutler & Pickering 2445 M Street, NW Washington, D.C. 20037-1420 Telephone: (202) 663-6000 [ ] Check the box if the filing relates solely to preliminary communications made before the commencement of a tender offer. Check the appropriate boxes below to designate any transactions to which the statement relates: [X] third-party tender offer subject to Rule 14d-1. [ ] issuer tender offer subject to Rule 13e-4. [ ] going-private transaction subject to Rule 13e-3. [ ] amendment to Schedule 13D under Rule l3d-2. Check the following box if the filing is a final amendment reporting the results of the tender offer: [X] ================================================================================ This Amendment No. 4 (the "Amendment"), the final amendment, amends and supplements the Tender Offer Statement on Schedule TO filed by Danaher Corporation, a Delaware corporation ("Danaher"), and Phoenix Acquisition Corp., a Delaware corporation and an indirect, wholly-owned subsidiary of Danaher (the "Purchaser"), on June 21, 2001, as previously amended and supplemented (the "Schedule TO"), relating to the offer by the Purchaser to purchase all outstanding shares of common stock, par value $0.001 per share (the "Shares"), of Microtest, Inc., a Delaware corporation ("Microtest") at $8.15 per Share, net to the seller in cash, upon the terms and subject to the conditions set forth in the Offer to Purchase, dated June 21, 2001 (the "Offer to Purchase") and in the related Letter of Transmittal, copies of which are attached as Exhibits (a)(1) and (a)(2), respectively, to the Schedule TO. Items 1 through 9 and 11. Items 1 through 9 and 11 of the Schedule TO, which incorporate by reference the information contained in the Offer to Purchase, are hereby amended and supplemented by adding thereto the following: The Offer expired at 12:00 midnight, New York City time, on Monday, July 23, 2001. Pursuant to the Offer, based upon a preliminary report from the Depositary, the Purchaser accepted for payment 7,856,064 Shares, representing approximately 90.611% of the outstanding Shares (including 36,248 Shares tendered pursuant to guaranteed delivery). On July 24, 2001, Danaher issued a press release announcing the closing of the tender offer and its intention to acquire the remaining Shares through a cash merger, expected to be completed shortly. The full text of Danaher's July 24, 2001 press release is attached as Exhibit (a)(12) hereto and incorporated herein by reference. Item 12. Exhibits. Item 12 of the Schedule TO is hereby amended by adding thereto the following: (a)(12) Text of Press Release issued by Danaher on July 24, 2001. SIGNATURE After due inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct. Dated: July 24, 2001. PHOENIX ACQUISITION CORP. By /s/ Christopher C. McMahon ----------------------------------- Name: Christopher C. McMahon Title: Vice President and Secretary DANAHER CORPORATION By /s/ Christopher C. McMahon ----------------------------------- Name: Christopher C. McMahon Title: Vice President -- Controller EXHIBIT INDEX *(a)(1) Offer to Purchase, dated June 21, 2001. *(a)(2) Form of Letter of Transmittal. *(a)(3) Form of Notice of Guaranteed Delivery. *(a)(4) Form of Letter to Brokers, Dealers, Commercial Banks, Trust Companies and Other Nominees. *(a)(5) Form of Letter to Clients for use by Brokers, Dealers, Commercial Banks, Trust Companies and Other Nominees. *(a)(6) Text of press release issued by Danaher dated June 13, 2001 (filed with the Securities and Exchange Commission under cover of Schedule TO-C by Danaher on June 13, 2001 and incorporated herein by reference). *(a)(7) Text of press release issued by Fluke Networks, Inc. dated June 13, 2001 (filed with the Securities and Exchange Commission under cover of Schedule TO-C by Danaher on June 13, 2001 and incorporated herein by reference). *(a)(8) Guidelines for Certification of Taxpayer Identification Number on Substitute Form W-9. *(a)(9) Form of summary advertisement dated June 21, 2001. *(a)(10) Text of Press Release issued by Danaher on July 20, 2001. *(a)(11) Text of Press Release issued by Danaher on July 23, 2001. (a)(12) Text of Press Release issued by Danaher on July 24, 2001. *(d)(1) Agreement and Plan of Merger, dated June 12, 2001, among Danaher, the Purchaser and Microtest. *(d)(2) Confidentiality Agreement, dated February 25, 1999, between Danaher and Microtest, as amended May 22, 2001. (g) None. (h) Not applicable. --------- *Previously filed