"The Fairbanks Rigid Weldless Caster features one-piece construction to eliminate stress build-up. Double ball raceways and seal ring keep lubrication in and dirt out. 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. Wheel Diameter in. 5, Foot Brake No, Mount Height in. 6 1/2, Wheel Width in. 2, Capacity lbs. 550, Material Type Steel, Top Plate Dimensions L x W in. 4 1/2 x 4, Casters qty. 1, Finish Type Gray epoxy, Bearing Type Plain, Overall Height in. 6 1/2, Caster Type Rigid, Wheel Type Polyolefin, Bolt Hole Spacing 3-3 5/8 x 2 5/8-3. One piece fork assures less failure and longer life Durable epoxy powder-coat finish Sturdy polyolefin wheel 550 lbs. capacity"