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 lifting nut is intended fit the CURT directweld square jack 28512 It is threaded lifting nut with a grease retaining structure for fluid movement