Trailer hitch lock is 5/8 inch diameter hitch pin with 3.54 inch effective length, perfect for class III/IV 2"&2.5" receiver tubes. Tow receiver hitch lock is perfect for trailer, towing, Boat, RV, Truck or Car. Use receiver pin lock to ensure trailer safety.Trailer hitch locks have an advanced hardened steel structure which is firm, solid and hard to bend. Chromed plating provides excellent rust and corrosion resistance in rough weather. Towing hitch lock is reliable construction for long term use.Hitch pin lock is so easy to operate. Only take down locking head then make pin into the receiver to press with locking head (keyless push design), you will hear "click" to know its working. Operation is successful now turn 1/4 clockwise with keys to unlock, anti-theft lockable pin will pop-up automatically.All weather rubber key slot cover protects keyhole from moisture, dust, and rust. 360-degree rotating head makes it easy to operate. Zinc alloy keyhole improves hitch locking pin anti-theft ability.If you have any question about tow receiver hitch lock, please feel free to contact us right away. Meets ANSI/ASME PASE safety standards and includes limited 1 year manufacturer guarantee.