Abstract: A replaceable, closed, container, cartridge or supply-item cassette holds a roll of stitcher wire from which U-shaped wire staples are to be formed by operation of a stitcher. The wire's end is led from the cassette to the stitcher by way of a flexible tube that terminates in a coupler/handle member. The coupler/handle member includes a releasable wire clamp that is operable to hold the wire's end. The coupler/handle member is constructed and arranged to protect the operator's hands from contact with the wire's sharp, needle-like end. When the coupler/handle member is locked or coupled to the stitcher, the stitcher's wire feed rollers automatically move to a nip-closed position, to entrap the end of the wire, and the wire is automatically released from the wire clamp. The stitcher's wire feed rollers are driven by a stepping motor. The cassette includes a brake that is operable to control the orderly feeding or wire by the stepping motor.