These heavy duty replacement car dolly casters are not the junk that comes on most car dollies. These casters feature higher capacities, larger wheels, ball bearings in the wheel for easier rolling, and a strengthened rig. Each caster provides 625 pounds of capacity for a total of 2,500 pounds of capacity for the set of four. These casters fit the Merrick Machine Auto Dolly and any other car dolly that has a half inch holes where the stem goes through. The larger diameter wheels also handle expansion joints better than the smaller ones and they are non-marking. Each caster comes with matching nut and lock washer. Caster specifications: Wheel Diameter 2-1/2”, Wheel Width 2”, Overall Height 3-1/4”, Stem Size ½”, Stem Length 13/16”.