Combination seal/thrust retainer washers protect the bearing from dirt, water, and chemicals. The zinc plated finish provides durability under any condition, while the semi-steel wheels are abrasion resistant and rugged, maintaining effortless rolling under heavier loads, and provides a cost-effective solution over steel wheels. It has a split outer race shell into which the roller assembly is inserted. Service Caster is unsurpassed in quality, reliability, and excellent customer service.