Exhibit 10.18

FOURTH AMENDMENT TO REVOLVING CREDIT AND SECURITY AGREEMENT,  TERM LOAN AND SECURITY AGREEMENTS, AND RELATED DOCUMENTS

This Fourth Amendment to Revolving Credit and Security Agreement, Term Loan and Security Agreements, and Related Documents ("Agreement") is executed by ALLIED
MOTION TECHNOLOGIES, INC. ("Allied Motion"), MOTOR PRODUCTS CORPORATION ("Motor Products"), ALLIED MOTION CONTROL CORPORATION ("Allied Motion Control"), EMOTEQ CORPORATION ("Emoteq"), COMPUTER
OPTICAL PRODUCTS, INC. ("Computer Optical"), AMOT I, INC. ("AMOT I"), AMOT II, INC. ("AMOT II"), AMOT III, INC. ("AMOT III"), STATURE ELECTRIC, INC. f/k/a
AMOT, Inc. ("New Stature"), AHAB INVESTMENT COMPANY ("Ahab"), PNC BANK, NATIONAL ASSOCIATION ("Agent") as agent for itself, Silicon Valley Bank, and any other lenders under the Revolving Credit
Agreement (collectively "Lenders"), PNC BANK, NATIONAL ASSOCIATION ("PNC"), and SILICON VALLEY BANK ("SVB") for valuable consideration, the receipt and sufficiency of which is hereby acknowledged, as
of November 1, 2005. Hereinafter, Allied Motion, Motor Products, Emoteq, Computer Optical, AMOT I, AMOT II, AMOT III, New Stature, and Ahab may be referred to individually as a "Borrower" and
collectively as the "Borrowers."

Recitals

A.    Borrowers
executed and delivered to Agent and Lenders a Revolving Credit and Security Agreement and other loan documents on and after May 7, 2004. Hereinafter, the
Revolving Credit and Security Agreement and any amendments, modifications, replacements or substitutions thereto may be referred to collectively as the "Revolving Credit Loan Agreement" and the
Revolving Credit Loan Agreement, any related loan documents, and any amendments, modifications, replacements or substitutions to any of the foregoing may be referred to collectively as the "Revolving
Credit Loan Documents".

B.    Borrowers
executed and delivered to PNC a Term Loan and Security Agreement and other loan documents on and after May 7, 2004. Hereinafter, the Term Loan and
Security Agreement and any amendments, modifications, replacements or substitutions thereto may be referred to collectively as the "PNC Term Loan Agreement" and the PNC Term Loan Agreement, any
related loan documents, and any amendments, modifications, replacements or substitutions to any of the foregoing may be referred to collectively as the "PNC Term Loan Documents.

C.    Borrower
executed and delivered to SVB a Term Loan and Security Agreement and other loan documents on and after May 7, 2004. Hereinafter, the Term Loan and
Security Agreement and any amendments, modifications, replacements or substitutions thereto may be referred to collectively as the "SVB Term Loan Agreement" and the SVB Term Loan Agreement, any
related loan documents, and any amendments, modifications, replacements or substitutions to any of the foregoing may be referred to collectively as the "SVB Term Loan Documents".

D.    Borrowers
wish to modify the Revolving Credit Loan Documents, PNC Term Loan Documents, and SVB Term Loan Documents (collectively "Loan Documents") as set forth in this
Agreement.

E.    Agent,
Lenders, PNC and SVB are unwilling to modify the Loan Documents unless Borrowers execute and agree to abide by the terms and conditions set forth in this
Agreement.

Agreements

1.     Borrowers
hereby acknowledge the validity and enforceability of the Loan Documents and reaffirm the truth and accuracy of all of the representations, warranties and other
statements contained in the Loan Documents as of the date of this Agreement.

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2.     The
outstanding principal balance on Borrowers' obligations to Lenders under the Revolving Credit Loan Documents amounted to approximately $4,737,432.33 as of
November 1, 2005 and interest, fees, and expenses are accruing thereon as set forth in the Revolving Credit Loan Documents.

3.     The
outstanding principal balance on Borrowers' obligations to PNC under the PNC Loan Documents amounted to approximately $3,990,880.00 as of November 1, 2005 and
interest, fees, and expenses are accruing thereon as set forth in the Loan Documents.

4.     The
outstanding principal balance on Borrowers' obligations to SVB under the SVB Loan Documents amounted to approximately $1,624,999.96 as of November 1, 2005 and
interest, fees, and expenses are accruing thereon as set forth in the Loan Documents.

5.Section 6.6of the Revolving Credit Loan Agreement hereby are amended to read:



6.Sections 5 and 6of the First Amendment to Revolving Credit and Security Agreement, Term Loan and Security
Agreements, and Related Documents among Borrowers, Agent, and Lenders dated as of August 19, 2004 hereby are amended to read:



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7.     Borrowers
hereby represent and warrant to Agent and Lenders that Premotec Beheer, B.V. has been merged into Allied Motion Technologies B.V.

8.     Borrowers
hereby release, waive and forever discharge Lender and its shareholders, directors, officers, employees, and agents from all known and unknown, absolute and
contingent, claims, defenses, setoffs, counterclaims, causes of action, actions, suits or other legal proceedings of any kind existing or accrued as of the date of this Agreement.

9.     Borrowers
shall be, jointly and severally, liable for the payment and performance of all of their present and future obligations under the Loan Documents and all of such
obligations shall be secured by all of the collateral described in the Loan Documents.

10.   Borrowers,
jointly and severally, hereby represent and warrant to and covenant with Lender that Lender's liens, security interests, encumbrances and claims against the
collateral described in the Loan Agreement and other Loan Documents shall continue to be prior and superior to any other liens, security interests, encumbrances or claims of any kind except for those
specifically provided otherwise in the Loan Documents. Borrowers, jointly and severally, represent and warrant to Lender that no event of default exists under the Loan Documents as of the date of this
Agreement and no material adverse changes have occurred in Borrowers' financial condition since the date of the last financial statements provided to Agent.

11.   The
Loan Documents shall remain in full force and effect except as amended by this Agreement and any additional Loan Documents.

12.   Borrowers,
jointly and severally, shall pay Lenders a loan modification fee in the amount of Fifteen Thousand and No/100 Dollars ($15,000.00) and all of Agent's,
Lenders', PNC's and SVB's attorneys' fees and other expenses incurred in connection with the negotiation, drafting, execution, filing and recording of this Agreement and any related Loan Documents.
The amounts described in this paragraph shall be in addition to, and not in lieu of, the interest, fees and other charges owing under the Loan Documents.

13.   Borrowers
shall take any additional actions and execute and deliver to Lender any additional documents reasonably requested by Lender to carry out the intent and
purposes of this Agreement and any related Loan Documents.

14.   This
Agreement and any related documents shall inure to the benefit of and be binding upon the successors and permitted assigns of the parties hereto.

15.   This
Agreement shall be governed by the laws of the State of Colorado.

16.   The
parties hereto consent to the jurisdiction and venue of any Court located in the City and County of Denver, State of Colorado, in the event of any litigation
pertaining to this Agreement or any

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related
Loan Document or the enforcement of any liability, obligation, right or remedy described therein.

17.   This
Agreement may be executed in counterparts and shall be effective when at least one (1) counterpart has been executed by each party hereto.

18.   This
Agreement and the various documents described herein represent the complete and integrated understanding between the parties pertaining to the subject matter
hereof. All prior and contemporaneous understandings and agreements, written or oral, express or implied, shall be of no further force and effect to the extent inconsistent herewith.

19.   THE
PARTIES HERETO WAIVE THEIR RESPECTIVE RIGHTS TO DEMAND A JURY TRIAL IN THE EVENT OF ANY LITIGATION PERTAINING TO THIS AGREEMENT, ANY RELATED LOAN DOCUMENTS, OR THE
ENFORCEMENT OF ANY LIABILITY, OBLIGATION, RIGHT OR REMEDY DESCRIBED THEREIN.

| |  | ALLIED MOTION TECHNOLOGIES INC.  
| |  | ---------------------------------
| |  | By:                              
| |  | Name:                            
| |  | Title:                           
| |  | MOTOR PRODUCTS CORPORATION       
| |  | By:                              
| |  | Name:                            
| |  | Title:                           
| |  | ALLIED MOTION CONTROL CORPORATION
| |  | By:                              
| |  | Name:                            
| |  | Title:                           
| |  | EMOTEQ CORPORATION               
| |  | By:                              
| |  | Name:                            
| |  | Title:                           
| |  | COMPUTER OPTICAL PRODUCTS, INC.  
| |  | By:                              
| |  | Name:                            
| |  | Title:                           
| |  |                                  

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| |  | AMOT I, INC.                                                                                                                            
| |  | ----------------------------------------------------------------------------------------------------------------------------------------
| |  | By:                                                                                                                                     
| |  | Name:                                                                                                                                   
| |  | Title:                                                                                                                                  
| |  | AMOT II, INC.                                                                                                                           
| |  | By:                                                                                                                                     
| |  | Name:                                                                                                                                   
| |  | Title:                                                                                                                                  
| |  | AMOT III, INC.                                                                                                                          
| |  | By:                                                                                                                                     
| |  | Name:                                                                                                                                   
| |  | Title:                                                                                                                                  
| |  | STATURE ELECTRIC, INC. f/k/a AMOT, Inc.                                                                                                 
| |  | By:                                                                                                                                     
| |  | Name:                                                                                                                                   
| |  | Title:                                                                                                                                  
| |  | AHAB INVESTMENT COMPANY                                                                                                                 
| |  | By:                                                                                                                                     
| |  | Name:                                                                                                                                   
| |  | Title:                                                                                                                                  
| |  | PNC BANK, NATIONAL ASSOCIATION, AS AGENT FOR ITSELF, SILICON VALLEY BANK AND ANY OTHER LENDERS UNDER THE REVOLVING CREDIT LOAN AGREEMENT
| |  | By:                                                                                                                                     
| |  | Name:                                                                                                                                   
| |  | Title:                                                                                                                                  
| |  |                                                                                                                                         

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| |  | PNC BANK, NATIONAL ASSOCIATION
| |  | ------------------------------
| |  | By:                           
| |  | Name:                         
| |  | Title:                        
| |  | SILICON VALLEY BANK           
| |  | By:                           
| |  | Name:                         
| |  | Title:                        

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