Fits all Williams 1-1/2″ Drive Sockets and Accessories. Crush Gage on the resin pin indicates when a socket is excessively worn and should be replaced. Securely retains sockets and accessories to square drive of impact wrench. For 1-1/2″ drive impact tools with pin retention hole and groove. Made of oil resistant material. RET RING® is a trademark of FTL Enterprises, inc.