LIMITED POWER OF ATTORNEY

       The undersigned hereby constitutes and appoints each of
Michael S. Turner and Andrew J. Sabino, each of 908 Devices Inc., signing
singly, and with full power of substitution, the undersigned's true and
lawful attorney-in-fact to:

	(1)	execute for and on behalf of the undersigned, from time to
time a Form ID, including any attached documents (such as Update Passphrase
Authentication), to effect the assignment of codes to the undersigned to be
used in the transmission of information to the U.S. Securities and Exchange
Commission ("SEC") using the EDGAR System; and

	(2)	take any other action of any type whatsoever in connection
with the foregoing which, in the opinion of such attorney-in-fact, may be
of benefit to, in the best interest of, or legally required by, the
undersigned, it being understood that the documents executed by such
attorney-in-fact on behalf of the undersigned pursuant to this Power of
Attorney shall be in such form and shall contain such terms and conditions
as such attorney-in-fact may approve in such attorney-in-fact's discretion.

	The undersigned hereby grants to each such attorney-in-fact, acting
singly, 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 if personally present, with
full power of substitution or revocation, hereby ratifying and confirming
all that such attorney-in-fact, or such attorney-in-fact's 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 attorneys-in-fact, in serving in such
capacity at the request of the undersigned, are not assuming, any of the
undersigned's responsibilities to comply with the Securities Exchange Act
of 1934, as amended. The undersigned hereby agrees to indemnify the
attorneys-in-fact from and against any demand, damage, loss, cost or
expense arising from any false or misleading information provided by the
undersigned to the attorneys-in-fact.

	This Power of Attorney shall remain in full force and effect until
the earlier of it being revoked by the undersigned in a signed writing
delivered to the foregoing attorneys-in-fact or superseded by a new power
of attorney regarding the purposes outlined herein as of a later date.
This Power of Attorney supersedes any prior power of attorney in connection
with respect to the subject matter of this Power of Attorney. This Power of
Attorney shall expire as to any individual attorney-in-fact if such
attorney-in-fact ceases to be an employee of 908 Devices Inc.

	IN WITNESS WHEREOF, the undersigned has caused this Power of
Attorney to be executed as of June 4, 2024.

						/s/Michele M. Leonhart
						Signature

						Michele M. Leonhart
						Print Name








[Signature Page to Limited Power of Attorney for EDGAR Codes]