Trimax UMAX100 Premium Universal 'Solid Hardened Steel' Trailer Lock (fits all couplers) One size fits most coupler types Dual ratchet lock System Exclusive design provides 360 degrees of hardened steel protection Key hole cover keeps out dirt Attractive Ballistic grade Nylon housing One size fits all (from 1-7/8", 2", to 2-5/15", all coupler types) Key hole cover slides up to seal out dirt and grime Attractive ballistic grade nylon housing absorbs hammer blows and protects against weather Type A key which is a spring loaded, 7 pin, high security key. Resists attempted drill outs. Rugged and durable, the key will not bend or break. Weighs 6 pounds