Polyurethane Tread on Steel Core Wheel 615 lb Load Rating 300 to 999 lb Load Rating Range 3 1/8 in Wheel Dia 1 5/8 in Wheel Width Polyurethane Wheel/Tread Material Firm 92 Shore A Precision Ball Standard Tread Shape 1/2 in For Axle Size Not Included Includes Spanner Bushing Steel Wheel Core Material Yes Non-Marking 1 9/16 in Hub Length