5/8" Hitch Lock (2" Receiver, Barbell, Black) Like a hitch pin and clip, a hitch lock is designed to insert into the fastener hole in the side of a receiver tube in order to hold a ball mount or hitch-mounted accessory in place. The hitch lock allow you to lock your ball mount into your trailer hitch, Deterring theft and preventing anyone from detaching your trailer at the ball mount and towing away your property without your permission. The hitch lock features a barbell design and comes with a 5/8" pin diameter to fit a 2" receiver tube size (usable pin length is 2.850"; will not work with double-walled receiver tubes). The barbell hitch locks are comprised of a pin with two end caps and a round locking mechanism. They are key-operated and activate with a simple 1/4-turn.