Mass. Gen. Laws ch. 106, § 2A-515: Acceptance of Goods

Section 2A–515. (1) Acceptance of goods occurs after the lessee has had a reasonable opportunity to inspect the goods and:

(a) the lessee signifies or acts with respect to the goods in a manner that signifies to the lessor or the supplier that the goods are conforming or that the lessee will take or retain them in spite of their nonconformity; or

(b) the lessee fails to make an effective rejection of the goods (Section 2A–509(2)).

(2) Acceptance of a part of any commercial unit is acceptance of that entire unit.