Trimax SXTC3 The SXTC3 features 100% stainless steel. Provides additional security for your camper, boat or trailer by securing the coupler of your trailer tongue. Also secures trailer door latches, cargo boxed and other types of doors. Features patented 1/4 turn technology that cannot be false locked. Provides dual force protection when used with the UMAX100 (sold separately). Patented dual lock lug design. Full length pin made of solid forged machined steel that cannot be pulled out. No internal springs to seize up or break. Knurling on lock heads adds style and grip. Stainless steel internal components. Double headed or dog bone style design. Width between heads (exposed pin length or gap space) is 3-1/2". 1/4" pin diameter. A coupler is the forward most part of a trailer tongue that envelopes and secures to the tow vehicle hitch ball. The lever on the coupler both allows the ball to be received into the coupler and prevents the ball from being removed. Accordingly, a coupler lever lock prevents the lever from moving into the open position. For maximum security when a trailer, boat or RV is hooked up to a vehicle, a coupler lever lock should be combined with an unattended trailer lock such as the UMAX100 or UMAX50. TRIMAX makes the world's toughest locks. Through value added engineering design, TRIMAX is committed to product innovation that holds up to the highest quality standards. TRIMAX provides maximum security for marine, trailer and tow, RV, performance truck, power sports and bicycle applications. Tested. Tough. TRIMAX. TRIMAX offers a lifetime warranty on all of their products.