Polyolefin Tread Wheel 600 lb Load Rating 300 to 999 lb Load Rating Range 4 in Wheel Dia 2 in Wheel Width Polyolefin Wheel/Tread Material Hard 75 Shore D Roller Standard Tread Shape 1/2 in For Axle Size Not Included Includes Spanner Bushing Plastic Wheel Core Material Yes Non-Marking 2 3/16 in Hub Length