Pneumatic wheels give mobility to heavy loads on smooth, hard surfaces and concrete floors with obstructions. Recommended for the protection of both loads and floor surface. Caster can also be used for outdoor terrain. Wheel absorbs shock and vibration. Caster swivels 360° and has a 220 lb. load rating. Heavy Duty bolted steel wheel hub is equipped with Ball Bearing and a 1/2 in. axle. Large diameter main load bearing and thrust bearing assures easy maneuvering under heavy loads. Sawtooth design rubber tire is rated at 50 PSI and is 4 Ply. Lube fittings for swivel and wheel bearings. Color: Black.