Solid Polyurethane Wheels (4", 5", 6", 8")Expertly crafted and engineered for superior performance No risk of tread separation, corrosion, water absorption, or leaving marks on floors Highly resistant to a wide range of chemicals, oils, acids, greases, and other contaminants Ideal for environments requiring frequent washing or where water exposure is prevalent Feature Description Wheel Material Solid polyurethane wheels Wheel Diameter Options 4", 5", 6", 8" Wheel Width Options 1. 5" and 2"