Ultra Fab Products 10-2219 Swivel Hitch Bar Mount Skid Wheel Drop forged caster is superior in strength to other casters Extra strong metal wheels with roller bearings and 1/4-inch urethane on outer edge Prevents tail dragging and digging while backing up, helps protect undercarriage from damage Easy bolt-on installation; two per box Fits 2-1/2" or 3" hitch bars