Polyurethane Tread on Iron Core Wheel 375 lb Load Rating 300 to 999 lb Load Rating Range 4 in Wheel Dia 1 1/2 in Wheel Width Polyurethane Wheel/Tread Material Firm 95 Shore A Delrin Standard Tread Shape 3/8 in For Axle Size Not Included Includes Spanner Bushing Iron Wheel Core Material Yes Non-Marking 1 3/4 in Hub Length