The TowSmart Adjustable Coupler Locking Pin Fits 1 to 3 Coupler Spans Silver 7274 protects your boats campers trailers equipment and other valuable assets from theft. The Coupler Lock secures the trailer to the ball mount when in tow and provides superior protection to the trailer when it is left unattended. It is designed to fit 1 7/8 in 2 in. and 2 5/16 in. Couplers and provides a dust cover to protect the lock from corrosion build up. It is easy to install provides a tight and secure fit and is made of corrosion-resistant materials designed to withstand harsh weather conditions. This product is not recommended to remain on vehicles for an extended period of time. Includes 2 keys.