Exhibit 3.17

                          CERTIFICATE OF INCORPORATION

                                       OF

                               NTK INVESTMENT CO.

1. The name of this corporation is NTK Investment Co.

2. Its registered office in the State of Delaware is located at Corporation
Trust Center, 1209 Orange Street, City of Wilmington, County of New Castle. The
name of its registered agent at such address is The Corporation Trust Company.

3. The purpose of this corporation is to engage in any lawful act or activity
for which corporations may be organized under the General Corporation Law of the
State of Delaware, and to have as additional purposes all powers granted to
corporations by the laws of said State, provided that no such purpose shall
include any activity inconsistent with the General Corporation Law of said
State.

4. The total number of shares of stock that this corporation shall have
authority to issue is 1000 shares of Common Stock, par value $1.00 per share.
Each share of stock shall be entitled to one vote.

5. The name and mailing address of the incorporator is: John R. Potter, Vice
President and General Counsel, Nortek, Inc., 815 Reservoir Avenue, Cranston,
Rhode Island 02910.

6. The election of directors need not be by ballot unless the by-laws shall so
require. Subject to the limitations and exceptions, if any, contained therein,
by-laws may be adopted, amended or repealed by the board of directors.

7. The corporation shall indemnify each person who is or was a director or
officer of this corporation against expenses (including attorney's fees),
judgments, fines and amounts paid in settlement to the maximum extent permitted
from time to time under the General Corporation Law of the State of Delaware.
Such indemnification shall not be exclusive of other indemnification rights
arising under any by-law, agreement, vote of directors or stockholders or
otherwise and shall inure to the benefit of the heirs and legal representatives
of such person.

8. The books of the corporation may (subject to any statutory requirements) be
kept outside the State of Delaware as may be designated by the board of
directors or in the by-laws of the corporation.

9. The corporation reserves the right to amend, alter, change or repeal any
provision contained in this certificate of incorporation, in the manner now or
hereafter prescribed by statute, and all rights conferred upon stockholders
herein are granted subject to this reservation.

I, THE UNDERSIGNED, being the incorporator hereinbefore named for the purpose of
forming a corporation pursuant to the General Corporation Law of the State of
Delaware, do make this



certificate, hereby declaring and certifying that the facts herein stated are
true, and accordingly have hereunto set my hand this 12th day of October, 1984.

                                            /s/ John R. Potter
                                          ------------------------
                                                John R. Potter

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                       CERTIFICATE OF OWNERSHIP AND MERGER
                               (Under Section 253
                                     of the
                      General Corporation Law of Delaware)

      The undersigned, being the President of NTK Investment Co., a Delaware
Corporation, hereby certifies that:

      1. NTK Investment Co. owns 92.1% of the outstanding shares of each class
of stock of Jensen Industries, a California corporation.

      2. A copy of the resolutions of the Board of Directors of NTK Investment
Co. to merge Jensen Industries with and into itself and assume all of its
obligations is attached hereto as Exhibit 1. Such resolutions state the terms
and conditions of the merger, including. the cash to be paid upon the surrender
of each share of Jensen Industries not owned by NTK Investment Co.

      3. The name of the surviving corporation shall be changed to Jensen
Industries, Inc., upon the effective date of the merger.

      IN WITNESS WHEREOF, the undersigned has subscribed this certificate and
hereby affirms that its contents are true this 19th day of March, 1985.

                                                 /s/ Richard L. Bready
                                                -----------------------
                                                Richard L. Bready
                                                President

Attest:

 /s/ John R. Potter
-----------------------
John R. Potter, Secretary

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