In our goal of being your best source for all things towing, the CURT line of trailer jacks is designed with care and manufactured with pride. CURT jacks are made with quality to promote the life and function of your trailer, and they come in several different styles to accommodate your needs, whether you are a frequenter of the boat landing, the campground, the racetrack or the farm. This replacement retainer pin is intended to fit a CURT pipe-mount swivel jack. It inserts into the pipe mounting bracket and keeps it set in place in the vertical position to support the trailer or folded position during travel. It features a 9/16" pin diameter to fit the male pipe mount #28931 and comes with a 3-1/2" chain for convenient attachment.