"Solid rubber caster never goes flat. Flat-free casters keep your equipment rolling over the toughest conditions, eliminating costly and inconvenient flat tires. Load handling characteristics are similar to air-filled tires, except now troublesome flat tires are a thing of the past. Capacity lbs. 175, Wheel Type Flat free, Wheel Diameter in. 6, Finish Type Zinc plated, Casters qty. 1 Wheel only. 6in. diameter 175-lb. load capacity 5/8in. ball bearing bore Zinc-plated steel wheel and brackets Sold individually"