POWER OF ATTORNEY

     KNOW ALL BY THESE PRESENTS, that the undersigned hereby authorizes
Michael G. Campbell, Jeffrey L. Quillen, Ryan M. Rourke Reed and Stacie S.
Aarestad, each acting singly, to execute and caused to be filed with the
United States Securities and Exchange Commission any and all documents or
filings, including any amendments thereto, required to be so filed.
The undersigned hereby grants to the attorney-in-fact full power and authority
to do and perform any and every act and thing whatsoever requisite, necessary
or proper to be done in the exercise of any of the rights and powers herein
granted, as fully to all intents and purposes as the undersigned might or could
do personally present, with full power of substitution, resubstitution or
revocation, hereby ratifying and confirming all that such attorney-in-fact,
or such attorney's-in-fact substitute or substitutes, shall lawfully do or
cause to be done by virtue of this power of attorney and the rights and powers
herein granted. The undersigned acknowledges that the foregoing attorney-in-
fact, in serving in such capacity at the request of the undersigned, is not
assuming any of the undersigned's responsibilities to comply with all
applicable laws, including Sections 13 and 16 of the Securities Exchange Act
of 1934.

     This Power of Attorney shall remain in full force and effect until revoked
by the undersigned in a signed writing delivered to the foregoing attorney-in-
fact.

     IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to
be executed as of this 11th day of August, 2022.

/s/ Jeffrey S. Hackman
Name: Jeffrey S. Hackman