Eliminate costly and inconvenient downtime with Marathon's Flat-Free 20" Tire and Wheel Assembly. The flat-free tire comes pre-mounted on a heavy-duty black composite plastic wheel with a 2.465" centered hub and 3/4" bearings installed. Additional 5/8" bearings are included for easy customization. Compatible with many outdoor carts and wagons including the Big Wheel Rubbermaid cart, marina and dock carts, yard carts and other two-wheeled carts. The tire is made of solid, polyurethane foam that has the same bounce and handling feel as an air-filled tire. Non-marking knobby tread tires will keep working surfaces clean and will not deteriorate in the elements. All with the added benefit of eliminating the hassle and maintenance of dealing with flat tires. Please check your existing tire measurements to ensure proper replacement fit. Not for highway use. The Marathon brand by Marastar features a full line of air-filled and flat-free tire and wheel assemblies for lawn and garden and commercial/industrial equipment. Count on Marathon for quality, easy to install products at a great value.