Marathon Flat Free tires provide the bounce and load handling characteristics similar to an airfilled tire with the benefit of never going flat, Flat free tire made of solid polyurethane foam, nonmarking, centipede tread, Perfect for small hand trucks, carts, and more, 2, 802, 504 narrow tire, 8, 5 tire diameter, 2, 4 tire width, 3 centered hub, 12 ball bearings, SKU: MTNI074