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                                                                     Exhibit 4.1

                                                                  EXECUTION COPY

                                VOTING AGREEMENT


         VOTING AGREEMENT, dated May 2, 2000 (the "Agreement"), by and among
Berwind Group Partners, a Pennsylvania partnership ("Investor"), MLGA Fund II,
L.P., a Delaware limited partnership ("MLGA") and Thomas L. Auth, an individual
("Auth").

                                   Background

         A. SLC Technologies, Inc. ("SLC") and ITI Technologies, Inc. ("the
Company") have entered into an Agreement and Plan of Merger dated as of
September 28, 1999, as amended (the "Merger Agreement"). Capitalized terms used
but not defined herein shall have the meanings ascribed to them in the Merger
Agreement. Pursuant to the Merger Agreement, SLC will be merged with and into
the Company (the "Merger"), with the Company as the surviving corporation (the
"Surviving Corporation"), and each issued and outstanding share of capital stock
of SLC shall be converted into and exchanged for 15.17064 shares of ITI Common
Stock.

         B. In accordance with the terms of the Merger Agreement, the Board of
Directors of the Company has the right to designate two individuals who are
members of the Board of Directors of the Company prior to the Effective Time to
serve as directors of the Surviving Corporation . The Company has designated
Auth and Perry J. Lewis ("Lewis") to serve as directors on the Board of
Directors of Surviving Corporation immediately after the Effective Time.

         C. Investor is the sole shareholder of SLC and, after the Merger,
Investor will own in excess of 60% of the issued and outstanding shares of ITI
Common Stock. In connection with the Merger, Investor has agreed to vote its
shares of ITI Common Stock in favor the election of certain individuals as
directors of the Surviving Corporation in accordance with the terms of this
Agreement.

                                      Terms

         In consideration of the mutual covenants contained herein and intending
to be legally bound hereby, the parties hereto agree as follows:

         1. Representations, Warranties and Covenants of Investor. Investor
represents and warrants that it has the requisite legal right, power and
authority to enter into this Agreement and to perform its obligations hereunder
without the need for the consent of any other person; and this Agreement has
been duly authorized, executed and delivered and constitutes the legal, valid
and binding obligation of it enforceable against Investor in accordance with the
terms hereof.

         2. Representations, Warranties and Covenants of MLGA. MLGA represents
and warrants that it has the requisite legal right, power and authority to enter
into this Agreement
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and to perform its obligations hereunder without the need for the consent of any
other person; and this Agreement has been duly authorized, executed and
delivered and constitutes the legal, valid and binding obligation of MLGA
enforceable against it in accordance with the terms hereof.

         3. Representations, Warranties and Covenants of Auth. Auth represents
and warrants that he has the requisite legal right, power and authority to enter
into this Agreement and to perform his obligations hereunder without the need
for the consent of any other person; and this Agreement has been duly
authorized, executed and delivered and constitutes the legal, valid and binding
obligation of Auth enforceable against him in accordance with the terms hereof.

         4. Directors and Voting Agreements. Subject to Sections 5, 6 and 7
hereof, Investor agrees that until the second anniversary of the Closing Date it
will vote all shares owned by it (including executing and delivering written
consents) for the following individuals as directors of the Surviving
Corporation: (a) Auth, who will serve as Chairman of the Board of Directors of
the Surviving Corporation, and (b) Lewis, but only so long as he and his
Controlled Affiliates collectively own (beneficially and of record) at least 25%
of the shares of ITI Common Stock collectively owned by him and his Controlled
Affiliates on the date hereof. As used herein, "Controlled Affiliate" means
MLGA, MLGAL Partners, L.P., John A. Morgan and Sangwoo Ahn.

         5. Right to Fill Certain Vacancies in Surviving Corporation's Board. In
the event that a vacancy is created on the Board of Directors of the Surviving
Corporation during the two-year period commencing on the Closing Date by the
death, disability, retirement, resignation or removal for Cause of a director
specified in Section 4 (or a successor thereto appointed pursuant to this
Section 5), Investor will promptly to consent in writing or vote or cause to be
voted all of the shares of ITI Common Stock owned by it to and will cause the
directors elected by it to (a) in the case of a vacancy left by Auth, to elect
an individual designated by the majority of the individuals who were directors
of the Company immediately prior to the Effective Time to fill such vacancy and
serve as a director and (b) so long as MLGA meets the ownership test of Section
4(b), in the case of a vacancy left by Lewis, to elect an individual designated
by MLGA to fill such vacancy and serve as a director.

         6. Transfer of Shares by Investor. If Investor transfers any shares of
ITI Common Stock that it receives in connection with the Merger, then Investor
shall cause such transferee to execute a joinder to this Agreement whereby the
transferee agrees to be bound to the same terms of this Agreement to which
Investor is bound.

         7. Right to Remove Directors. Notwithstanding Section 4, Investor may
take all action necessary to remove a director specified in Section 4 (or a
successor thereto appointed pursuant to Section 5 hereof) if Cause (defined
below) exists for such removal. As used herein, "Cause" means (i) theft,
misappropriation or embezzlement of the funds of the Surviving Corporation or
(ii) conviction of any felony, crime involving fraud or misrepresentation, or of
any other crime the effect of which is likely to adversely affect on the
Surviving Corporation;

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provided, however, that Investor shall not vote its shares of ITI Common Stock
to remove for cause the directors designated in Section 4 unless a majority of
the entire Board of Directors of the Surviving Corporation affirmatively
determines that, in good faith, such director was guilty of the type of conduct
set forth above and specifying the particulars thereof in reasonable detail. In
the event any person ceases to be a director, such person shall also cease to be
a member of any committee of the Board of Directors of the Surviving
Corporation.

         8. Termination. This Agreement will terminate on the second anniversary
of the Closing Date.

         9. Amendment and Modification. This Agreement may be amended or
modified, or any provision hereof may be waived, provided that such amendment or
waiver is set forth in a writing executed by the parties hereto.

         10. Successors and Assigns; Entire Agreement. This Agreement and all of
the provisions hereof shall be binding upon and inure to the benefit of the
parties hereto and their respective successors and permitted assigns and
executors, administrators and heirs. This Agreement sets forth the entire
agreement and understanding among the parties as to the subject matter hereof
and merges and supersedes all prior discussions, agreements and understandings
of any and every nature among them.

         11. Governing Law. The validity, performance, construction and effect
of this Agreement shall be governed by and construed in accordance with the
internal law of the State of Delaware, without giving effect to principles of
conflicts of law.

         12. Headings. The headings in this Agreement are for convenience of
reference only and shall not constitute a part of this Agreement, nor shall they
affect its meaning, construction or effect.

         13. Counterparts. This Agreement may be executed in two or more
counterparts and by the parties hereto in separate counterparts, each of which
when so executed shall be deemed to be an original, and all of which taken
together shall constitute one and the same instrument.

         14. Further Assurances. Each party shall cooperate and take such action
as may be reasonably requested by another party in order to carry out the
provisions and purposes of this Agreement and the transactions contemplated
hereby.

         15. Remedies. In the event of a breach or a threatened breach by any
party to this Agreement of its obligations under this Agreement, any party
injured or to be injured by such breach, in addition to being entitled to
exercise all rights granted by law, including recovery of damages, will be
entitled to specific performance of its rights under this Agreement. The parties
agree that the provisions of this Agreement shall be specifically enforceable,
it being agreed by the

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parties that the remedy at law, including monetary damages, for breach of such
provision will be inadequate compensation for any loss and that any defense in
any action for specific performance that a remedy at law would be adequate is
waived.

         16. No Third Party Beneficiaries. Nothing in this Agreement, express or
implied, is intended to or shall confer upon any other person any rights,
benefits or remedies of any nature whatsoever under or by reason of this
Agreement.

         IN WITNESS WHEREOF, the parties hereto have executed this Agreement as
of the day and year first above written.


                                           BERWIND GROUP PARTNERS


                                           By:  /s/ BRUCE J. MCKENNEY
                                              ---------------------------------
                                           Name: Bruce J. McKenney
                                           Title:   Senior Vice President


                                           /s/ THOMAS L. AUTH
                                           ------------------------------------
                                           Thomas L. Auth


                                           MLGA FUND II, L.P.

                                           By:  MLGAL PARTNERS, L.P.,
                                              ---------------------------------
                                                its general partner


                                           By:  /s/ PERRY J. LEWIS
                                              ---------------------------------
                                           Name:
                                           Title:



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