The first caster in the history of the industry to be specifically designed for laundries. R&B's proprietary patented thread guard design, has been rigorously tested and will outperform your expectations in minimizing lint & thread pick up. A real time saver! - the NEW 5" tapered polyurethane wheel creates less floor friction and therefore less material build up on the wheel. - The heavy duty hardened steel yoke incorporates a sealed bearing raceway that minimizes dirt contamination and will outperform them all in both performance and durability. - The NEW Dual Sealed Precision bearing system is the best yet for smooth rolling and high performance for years to come.