This replacement clip for the Rebellion XD ball mount is designed to mount onto the vertical shank of the mount. It has a 1-1/4" hole to accept a trailer ball with a 1-1/4" diameter shank. The Rebellion XD adjustable ball mount is a leap forward in cushion hitch technology. It provides more control, confidence and a more comfortable ride, all while protecting your towing system from jerking, jarring and rattling. The Rebellion XD is not included in this package and must be purchased separately.