A piece of buttress material (936) and an end-effector of a surgical instrument including features which can aid a surgeon in properly and quickly attaching the piece of buttress material (936) to the end-effector. In various embodiments, a piece of buttress material (936) can include retention features (910) which can be engaged with portions of an end-effector to releasably retain the piece of buttress material (936) to at least a portion of the end-effector. Similarly, an end-effector can include features (910) configured to engage portions of a piece of buttress material (936) to releasably retain the piece of buttress material (936) to the end-effector. In at least one embodiment, more than one piece of buttress material can be releasably retained to an end-effector.
