Colson 2-series medium duty casters for threaded stem applications. Warehouse, factory and institutional applications casters. Non-marking, superior performing wheel materials like Thermoplastic Elastomer (TPE), Polyurethane, Polyolefin and our new "Quik Start" TPR with precision ball bearings to choose from. All choices include double ball hardened bearing race for better performance and zinc plated finish. Many options available upon request including wheel brakes, race seals and total lock brakes.