Contractor Grade. Perfect tire for Wheelbarrows Carts and Other Small Equipment. Multiple Hub and Axle Options Available. Choose between Ribbed Smooth and Knobby Treads. Tire Material:Solid Polyurethane. Rim Type: Steel. Rim Diameter: 8 . Outside Diameter: 15.5 . Width: 3.6 . Centered Hub: 6 . Ball Bearing: 5 8 . With Ribbed Tread. Load Capacity: 500 lbs. Not for Highway Use.