"Fairbanks Polyolefin Swivel Caster is constructed of cold-forged steel with steel ball bearings and double ball bearing raceways. Mount Height in. 5, Caster Type Swivel, Bolt Hole Spacing 1 3/4 x 2 7/8, Bearing Type Plain, Top Plate Dimensions L x W in. 2 3/8 x 3 5/8, Foot Brake No, Wheel Type Polyolefin, Finish Type Zinc plated, Overall Height in. 5, Wheel Width in. 1 1/4, Material Type Steel, Wheel Diameter in. 4, Casters qty. 1, Capacity lbs. 255. Double-ball raceway for added strength and swivel ability Rugged 1/2in. kingpin Zinc electro-galvanized finish prevents rust and maintains bright look Rugged polyolefin wheel 255-lb. capacity"