The Carlyle Tools 10mm Lock-A-Socket is designed to keep 10mm sockets secure in one place. The rail holds 10 sockets, with five 1/4” posts and five 3/8” posts. The underside contains a full-length, high-powered magnet that allows the user to store their 10mm Lock-A-Socket on most metal surfaces without scratching the paint. Simply twist the socket to the right to lock the socket in place, and twist to the left to unlock the socket. The unit measures 11.5” in length, 1.5” in width, and 1.25” in height.