Trimax UMAX100 Premium Universal Dual Purpose Coupler Lock

360 degrees of solid steel protection against trailer theft. The UMAX100 is constructed of solid hardened steel and fits most coupler sizes (1 7/8" to 2 5/16"). A 5/8" (16mm) hardened steel shackle helps ensure your trailer is secure, even when left unattended. It has a patented dual locking system, hardened steel crossbar and ball, and ballistic grade nylon housing for maximum security.