CURT Trailer Hitch Lock, 5/8-Inch Pin Diameter, Fits 2 or 2-1/2-Inch Receiver Model 23528CURT Trailer Hitch Lock, 5 8 Inch Pin Diameter, Fits 2 or 2 1 2 Inch Receiver Model 23528 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 m