8" x 2" Colson Performa Wheel Rigid Caster - 600 lbs. Capacity8" x 2" Colson Performa Wheel Rigid Caster The Colson Performa wheel uses a proprietary thermoplastic rubber compound for its tread which is self healing if punctured or damaged. The crowned tread provides a smooth rolling experience and easy swivel while also providing cushion for rolling over bumps and thresholds. This wheel is designed to work well on a variety of rolling surfaces, and the specialized tread allows for a longer lifespan than a