Mass. Gen. Laws ch. 54 § 33G
If any special marking units or special tabulating units are leased or purchased by a city or town, the manufacturer or distributor of such units shall give to the city or town clerk a bond, with sufficient sureties, to keep such units in working order for at least two calendar years from the date of lease or purchase. Said manufacturer or distributor shall also give to said clerk a bond, with sufficient sureties, conditioned to defend and indemnify the city or town leasing the units against any suit at law or in equity and for any expense, damage or inconvenience which they may incur or suffer by reason of any suit brought against them for infringement of patents or other rights arising from the lease or use of such units.
Mass. Gen. Laws ch. 54, § 33G