5/8'' Hitch Pin and 1/4'' Trailer Coupler Locks with rubber caps can prevent it from water and dirt and keep the lock rust-free. It is easy to install, no drilling required.It fits for 5/8'' diameter receiver lock. It can save time and avoid fumbling with keys. Patented design engineered to increase durability and strength. It includes 4 keys and an all-weather rubber key slot cap. Single key lock design makes it simple to unlock and lock. It is perfect hitch accessory and easy to use.