Gator Grip Universal Socket switches both ordinary and metric sockets and wrenches. When the socket is placed on the fastener the center pins retract and the outer pins surround the fastener. After the fastener is turned, the torque gets transmitted to the walls of the socket through the outer pins making this socket a perfect choice for heavy-duty tasks. This universal socket fits standard ¼ inch to ¾ inch and metric 7 mm to 19 mm nuts and bolts heads. It has been designed with 54 hardened steel pins to ensure durability.