先来看一下Investopedia的解释：

“An implied warranty is a legal term for the assurances - written or oral - that a product is fit for the purpose intended and is merchantable, i.e., conforms to an ordinary buyer’s expectation.”

该术语的中文释义为“默示担保”，指法律、法规对产品质量有强制性要求，即使当事人之间有合同约定，也不能免除和限制这种义务。默示担保分为两类：适销性默示担保，保证产品满足买方的合理期待；适合特定用途的默示担保，保证产品满足买方的特定用途。

《美国统一商法典》第2-314条和第2-315条分别对两类默示担保作了规定：

§2-314. Implied Warranty: Merchantability; Usage of Trade.

(1) Unless excluded or modified (Section 2-316), a warranty that goods shall be merchantable is implied in a contract for their sale if the seller is a merchant with respect to goods of that kind. Under this section the serving for value of food or drink to be consumed either on the premises or elsewhere is a sale.

(2) Goods to be merchantable must be at least such as

(a) pass without objection in the trade under the contract description; and

(b) in the case of fungible goods, are of fair average quality within the description; and

(c) are fit for the ordinary purposes for which such goods are used; and

(d) run, within the variations permitted by the agreement, of even kind, quality and quantity within each unit and among all units involved; and

(e) are adequately contained, packaged, and labeled as the agreement may require; and

(f) conform to the promise or affirmations of fact made on the container or label if any.

(3) Unless excluded or modified (Section 2-316) other implied warranties may arise from course of dealing or usage of trade.

§2-315. Implied Warranty: Fitness for Particular Purpose.

Where the seller at the time of contracting has reason to know any particular purpose for which the goods are required and that the buyer is relying on the seller’s skill or judgment to select or furnish suitable goods, there is unless excluded or modified under the next section an implied warranty that the goods shall be fit for such purpose.