This 100mm polyurethane castors are made of a zinc plated housing which ensures the castor is robust enough and suitable for a variety of environments. The swiveling castor, with the red polyurethane wheel is strong and durable and suitable for moving machinery and equipment. The red polyurethane tire is bonded onto the polyamide nylon center making the castor very strong and durable. 3470UAR100P62 red787-1391 100mm Swivel Polyurethane Castor Red Wheel