An end effector assembly (5500) for use with a surgical instrument. The end effector assembly can include a fastener cartridge (5450), a plurality of fasteners, a first connector (5580a), a second connector (5580b), and a layer of material (5558) releasably secured to the fastener cartridge by the first connector and by the second connector. The layer of material can have a mount (5560) that extends into a slot (5456) or notch in the fastener cartridge between the first connector and the second connector when the layer of material is secured to the fastener cartridge. The layer of material can be a buttress material and/or a tissue thickness compensator. Further, the layer of material can have a reinforcement feature and/or a scalloped edge around at least a portion of the perimeter thereof.
