[Compatible with Most Hitches] The reciever lock is compatible with all I/II 1-1/4" x 1-1/4", III/IV/V 2" x 2" and 2-1/2" x 2-1/2" receivers (1/2" and 5/8" pin), suitable for bike rack and tray tow rope for trailer, truck, car, and boat. [Strong Traction] The 1/2" pin can tow up to 3,500 GTW, and the 5/8" pin can tow up to 20,000 GTW. The usable length of 1/2" pin is 2-1/2", and the usable length of 5/8" pin is 3-1/4". Strong traction makes it difficult to slip off. [Simple Operation] The lock adopts the design of push-to-lock without key. After unlocking the key can be removed. To open the lock, you just need to turn the key 1/4 turn, and the pin will automatically pop out. The swivel lock head rotates 360 degrees allowing keyway to conveniently face forward, which is easy to use and operate. [Higher Security and Theft Deterrence] The push lock function of the receiver lock can ensure locking safe every time, while towing, the receive lock provides higher security and theft deterrence. And the four-pin cylinder has higher security, effectively preventing lock picking. [High-quality Material] The receiver lock came with all-weather rubber snap-on cover, which provides weather resistance and prevents dirt from entering keyway. The lock pin is mainly made of stainless steel, which is anti-corrosion, sturdy and not easy to bend. And the key is made of copper and has a non-slip protective cover.