SECURITIES AND EXCHANGE COMMISSION
                          Washington, D.C.  20549

                                ----------

                                FORM 8-A/A
                              AMENDMENT NO. 2

             FOR REGISTRATION OF CERTAIN CLASSES OF SECURITIES
                  PURSUANT TO SECTION 12(b) OR (g) OF THE
                      SECURITIES EXCHANGE ACT OF 1934

                                ADT LIMITED
          ------------------------------------------------------
          (Exact name of registrant as specified in its charter)

           BERMUDA                             Not applicable
- ------------------------------               -------------------
(Jurisdiction of incorporation                 (IRS Employer
      or organization)                       Identification No.)


              Cedar House
           41 Cedar Avenue
         Hamilton HM12, Bermuda                  Not applicable
- -----------------------------------------        --------------
(Address of principal executive offices)*          (Zip Code)

         * ADT Limited maintains its registered and principal executive
           offices at Cedar House, 41 Cedar Avenue, Hamilton HM12 Bermuda.
           The executive offices of the subsidiary that supervises ADT
           Limited's subsidiaries' activities in North America are located
           at 1750 Clint Moore Road, Boca Raton, Florida 33431.  The
           telephone number there is (561) 988-3600.

           Securities to be registered pursuant to Section 12(b) of the Act:

         Title of each class   Name of each exchange on which
         to be so registered   each class is to be registered
         -------------------   ------------------------------
           Series A First      New York Stock Exchange
           Preference Share
           Purchase Rights

     Securities to be registered pursuant to Section 12(g) of the Act:
                                   None
                        --------------------------
                             (Title of Class)



       Item 1.  Description of Registrant's Securities to be Registered.

       The prior Description of Registrant's Securities to be Registered in
Amendment No. 1 to this Form 8-A, dated March 3, 1997, is hereby incorporated
by reference herein, and is amended by adding the following to the end of the
prior description:

       The Company entered into an Agreement and Plan of Merger, dated as of
March 17, 1997, (the "Merger Agreement") among the Company, Limited Apache,
Inc., a Massachusetts corporation and a direct, wholly owned subsidiary of the
Company ("Merger Subsidiary"), and Tyco International Ltd., a Massachusetts
corporation, ("Tyco") whereby Merger Subsidiary will merge with and into Tyco
(the "Merger") upon the terms and subject to the conditions set forth in the
Merger Agreement.

       On July 2, 1997, the Rights Agreement was amended by the Second
Amendment to Rights Agreement, dated as of July 2, 1997 (the "Second
Amendment"), a copy of which is attached as an exhibit hereto.  The Second
Amendment was effected (i) to reflect the fact of a reverse stock split of the
Company's Common Shares contemplated by the Merger Agreement by changing the
definition of "Common Shares" to refer, from and after the effectiveness of
the Reverse Stock Split (as defined in the Merger Agreement), to the common
shares of the Company, par value $0.20, as adjusted by the Reverse Stock Split
and (ii) to affirmatively provide that no Distribution Date shall occur and no
person shall become an Acquiring Person under the Rights Agreement, as
amended, by reason or as a result of the consummation of the Merger or any
other transactions contemplated by the Merger Agreement.

      Upon the Merger becoming effective, the authorized share capital of the
continuing public company following the Merger will consist of 750,000,000
common shares, par value $0.20. An additional 5,000,000 Preference Shares were
reserved for issuance upon exercise of the Rights.

      Item 2.   Exhibits

      4.  Form of Second Amendment to Rights Agreement between ADT Limited
          and Citibank, N.A., New York branch, as Rights Agent.



                                 SIGNATURE


Pursuant to the requirements of Section 12 of the Securities Exchange Act of
1934, the registrant has duly caused this registration statement to be signed
on its behalf by the undersigned thereto duly authorized.


                                       ADT LIMITED


                                       By:    /s/ Stephen J. Ruzika
                                              -----------------------------
                                       Name:  Stephen J. Ruzika
                                       Title: Chief Financial Officer,
                                              Executive Vice President and
                                              Director


                                       Dated: July 2, 1997


                                                                     EXHIBIT 4

                             SECOND AMENDMENT
                                    to
                             RIGHTS AGREEMENT



      SECOND AMENDMENT dated as of July __, 1997 ("this Amendment") between
ADT Limited, a Bermuda company limited by shares (the "Company") and
Citibank, N.A., New York branch, a national banking association organized
under the laws of the United States of America acting solely through its
branch located at 111 Wall Street, New York, NY 10043 (the "Rights Agent").

      WHEREAS, the above-mentioned parties have previously entered into
that certain Rights Agreement dated as of November 6, 1996, as amended (the
"Agreement");

      WHEREAS, the Company has entered into an Agreement and Plan of Merger
(the "Merger Agreement"), dated as of March 17, 1997, among the Company,
Limited Apache, Inc., a Massachusetts corporation and a direct, wholly
owned subsidiary of the Company ("Merger Subsidiary"), and Tyco
International Ltd., a Massachusetts corporation, ("Tyco") whereby Merger
Subsidiary will merge with and into Tyco (the "Merger") upon the terms and
subject to the conditions set forth in the Merger Agreement;

      WHEREAS, the Board of Directors deems it desirable and in the best
interests of its shareholders that the transactions contemplated by the
Merger Agreement be consummated;

      WHEREAS, Section 5.03(b)(i) of the Merger Agreement provides for a
Reverse Stock Split (as defined in the Merger Agreement) of the common
shares of the Company;

      WHEREAS, Section 5.17 of the Merger Agreement provides that prior to
the Effective Time (as defined in the Merger Agreement), the Company shall
amend the Agreement to affirmatively provide that no Distribution Date
shall occur and no person shall become an Acquiring Person by reason or as
a result of the consummation of the Merger or any other transactions
contemplated by the Merger Agreement;

      WHEREAS, such parties wish to amend the Agreement in the manner set
forth below.

      NOW, THEREFORE, the parties hereto agree as follows:

      1.  All capitalized terms used herein, unless otherwise defined
herein, shall have the meanings given them in the Agreement, and each
reference in the Agreement to "this Agreement," "hereof," "herein,"
"hereunder" or "hereby" and each other similar reference shall be deemed to
refer to the Agreement as amended hereby.  All references to the Agreement
in any other agreement between or among any of the parties hereto relating
to the transactions contemplated by the Agreement shall be deemed to refer
to the Agreement as amended hereby.

      2.  The definition of "Acquiring Person" in Section 1 is hereby
amended by adding the following proviso to the end of the first paragraph
of such definition:

      "; provided further that no person shall become an Acquiring Person
by reason or as a result of the consummation of the Merger or any other
transactions contemplated by the Merger Agreement."

      3.  The definition of "Common Shares" in Section 1 is hereby amended
by replacing the existing definition, in its entirety, with the following:

      ""Common Shares" means (i) prior to the effectiveness of the Reverse
Stock Split (as defined in the Merger Agreement), the common shares, par
value $0.10, of the Company and (ii) from and after the effectiveness of
the Reverse Stock Split, the common shares of the Company, par value $0.20,
as adjusted by the Reverse Stock Split; except that, when used with
reference to any Person other than the Company, "Common Shares" means the
capital stock of such Person with the greatest voting power, of the equity
securities or other equity interest having power to control or direct the
management, of such Person."

      4.  The definition of "Distribution Date" in Section 1 is hereby
amended by adding the following proviso to the end of such definition:

      "; provided that no Distribution Date shall occur by reason or as a
result of the consummation of the Merger or any other transactions
contemplated by the Merger Agreement."

      5.  The following definitions are hereby added to Section 1:

      ""Merger" means the merger of Merger Subsidiary with and into Tyco
upon the terms and subject to the conditions set forth in the Merger
Agreement."

      ""Merger Agreement" means the Agreement and Plan of Merger, dated as
of March 17, 1997, among the Company, Merger Subsidiary and Tyco."

      ""Merger Subsidiary" means Limited Apache, Inc., a Massachusetts
corporation and a direct, wholly owned subsidiary of the Company."

      ""Tyco" means Tyco International Ltd., a Massachusetts corporation."

      6.  This Amendment shall be shall be governed by and construed in
accordance with the laws of Bermuda.

      7.  This Amendment may be signed in any number of counterparts, each
of which shall be deemed an original, with the same effect as if the
signatures thereto and hereto were upon the same instrument.

      8.  Except as expressly amended hereby, the Agreement shall remain in
full force and effect.

      IN WITNESS WHEREOF, this Amendment has been duly executed as a deed
by the respective authorized officers of the parties hereto, in each case
as of the day and year first above written.




                                       ADT LIMITED


THE COMMON SEAL          )             By:
OF ADT LIMITED           )                 -----------------------
was affixed to this deed )             Name: S.J. Ruzika
in the presence of:      )             Title: Director

                                       By:
                                           -----------------------
                                       Name:  M.A. Ashcroft
                                       Title: Director



                                       CITIBANK, N.A.


                                       By:
                                           -----------------------
                                       Name:  Nancy Ward
                                       Title: Vice President

                                       111 Wall Street
                                       New York, NY 10043
                                       Attention: Mark Woodward