Cracked sockets and worn drive tools cause each other to turn excessively in relation to each other. Designed with a resin crush gauge to help identify when to replace worn sockets. Drive tool and socket should line up when in use and should not pinch the crush gauge. One piece construction, no loose parts. Pin is made of resin which allows the material to compress without breaking. Retaining rings are used to help secure sockets onto drive tools. The resin crush gauge on the pin helps indicate when a socket is excessively worn and should be replaced. The rotational forces are between the drive tool and the socket. They are not intended to bear any load. This action pinches the small fin or the crush gauge on these retaining rings. If the crush gauge is pinched, it is an indication that the socket and or the drive tool need to be replaced.