A powered surgical apparatus applying surgical fasteners to body tissue comprising: an elongate body defining a longitudinal axis a channel supported by said elongate body, the channel having a longitudinal slot a cartridge retained by said channel, the cartridge housing a plurality of surgical fasteners an anvil member pivotably mounted to the channel adjacent the cartridge, the anvil member and cartridge being relatively movable between an open position and a closed position, the anvil member having a longitudinal slot (294) a motor assembly having a rotatable drive shaft a power source for energizing the motor assembly and an actuating assembly driven by the motor assembly, the actuating assembly having an actuation sled configured to translate through the cartridge to eject the surgical fasteners therefrom, the actuation sled being driven by an actuation beam, the actuation beam being accommodated by the longitudinal slot of the channel and the longitudinal slot of the anvil member and the actuation beam having a cam roller for engaging the anvil member and a cam beam. The apparatus further comprises a switch including an outer contact layer, a medical insulating layer and an inner contact layer. The medical insulating layer has a slot arranged to permit contact between the outer and inner contact layers. The switch is wrapped about a circumference of the elongate body.
