CURT hitch locks 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. This CURT hitch lock features a barbell design and comes with a 5/8 Inch pin Diameter to fit a 2 Inch or 2-1/2 Inch receiver tube size. CURT 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. They also come with watertight dust caps to keep out the elements and prevent corrosion. For the ultimate in towing security, a hitch lock and coupler lock used together will provide security at both the vehicle-side and trailer-side of your towing setup. For your boat, ATV or camper, keep your toys more secure with CURT hitch locks.