Iron Tread Wheel, 650 lb Load Rating, 300 to 999 lb Load Rating Range, 4 in Wheel Dia., 1 1/2 in Wheel Width, Iron Wheel/Tread Material, Extra Hard, Roller, Standard Tread Shape, 3/8 in, 1/2 in For Axle Size, Included Includes Spanner Bushing, Plastic Wheel Core Material, Yes Non-Marking, 1 5/8 in Hub Length