One-piece construction eliminates stress build-up. Double ball raceways and seal ring keep lubrication in and dirt out. Corrosion-resistant grey epoxy finish. 2 5/8in. to 3in. x 3in. to 3 5/8in. bolt hole spacing. 3/4in. king pin. Top plate size 4in. x 4 1/2in. U.S.A. Capacity (lbs.): 600, Wheel Size (in.): 4 x 2, Mount Height (in.): 5 5/8, Bolt Hole Spacing: 2 5/8 to 3 x 3 to 3 5/8, Top Plate: 4 x 4 1/2, Wheel Type: Swivel, Material: Polyurethane, Finish Type: Grey epoxy, Includes (qty.): 1