4" x 2" Colson Performa Wheel Swivel Caster w/ Total Lock - 500 lbs. Capacity4" x 2" Colson Performa Wheel Swivel Caster w Total Lock Brake 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