Polyurethane Tread on Iron Core Wheel 750 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 90 Shore A Precision Ball Standard Tread Shape 1/2 in For Axle Size Not Included Includes Spanner Bushing Iron Wheel Core Material Yes Non-Marking 2 1/2 in Hub Length