Rigid Plate Caster Load Rating 600 lb. Wheel Dia 4 In. Wheel Width 2 In. Overall Height 5-5/8 In. Wheel Material Polyurethane Inside Bolt Hole Spacing 3 x 3 In. Outside Bolt Hole Spacing 2-5/8 x 3-5/8 In. Plate Type B Wheel Color Blue Core Material Polypropylene Wheel Bearings Stainless Roller Plate Size 4 x 4-1/2 In. Durometer 95 Shore A Core Color Black Mounting Bolt Dia 3/8 In. Frame Material Stainless Steel Plate Thickness 0.30 In. Frame Finish Stainless Steel