When performance and endurance are key concerns, 10 Inch Super Heavy Duty Polyurethane on Cast Iron Wheel Swivel Casters with Tread Lock, the high performance castor is world class, with a large opposed taper roller bearing in the swivel head, the castor can be power towed at up to 12kph over flat surfaces withourt opstructions, the steel passivated zinc plated frame is robot welded and the fully sealed greasable swivel head makes and easily maintainable and smooth running swivel, custom designed and manufactured in-house to specification.