Trimax TMC10 Coupler / Door Latch Lock (fits couplers to 3/4" span) Fits couplers with up to a 3/4" span Internal O-ring in lock keeps water, grime and dirt out of locking mechanism to ensure years of use Protective rubber cap protects keyhole from water, grime, and dirt 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 Protective rubber bumper prevents rattling and abrasion