CURT Black Trailer Hitch Lock, 5/8-Inch Pin Diameter, Fits 2-Inch Receiver Model 23518CURT Black Trailer Hitch Lock, 5 8 Inch Pin Diameter, Fits 2 Inch Receiver Model 23518 Make your tow vehicle and trailer more secure by keeping them locked up tight with a CURT hitch lock. 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. While a CURT hitch pin does offer sufficient strength for keeping your ball mount