The TMC10 features a Zinc alloy and a protective rubber bumper that prevents noisy rattling and abrasion to ensure your finish is not marked. Provides additional security for your camper, boat or trailer by securing the coupler on your trailer tongue. Also secures trailer door latches, cargo boxes and other types of doors. Features patented 1/4 turn technology that cannot be false locked. * 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. * LIFETIME WARRANTY * Features teeth inside the lock so the lock will not fall apart if cut