Exhibit 99.1

Joint Filing Agreement

In accordance with Rule 13d-1(k) under the Securities Exchange Act of 1934, as amended, the undersigned hereby agree to the joint filing on behalf of each of them of a statement on Schedule 13D and all amendments thereto with respect to the common stock of Microwave Filter Company, Inc., and that this Joint Filing Agreement (this “Agreement”) be included as an Exhibit to such joint filing. This Agreement may be executed in any number of counterparts all of which taken together shall constitute one and the same instrument.

In witness hereof, the undersigned hereby executed this Agreement this 8th day of June, 2018.

/s/ Daniel Zeff                        

Daniel Zeff

ZEFF HOLDING COMPANY, LLC

By: /s/ Daniel Zeff                   

Name: Daniel Zeff

Title: Manager

ZEFF CAPITAL, L.P.

By: Zeff Holding Company, LLC,

as general partner

By: /s/ Daniel Zeff                   

Name: Daniel Zeff

Title: Manager