Next Generation casters are maintenance-free casters made of glass-filled nylon. Stainless options feature 304 Stainless components, such as axles and mounting hardware, to increase chemical and water resistance. Stainless Steel precision bearings are insert-molded into the sealed raceway, providing a worry-free, smooth and quiet operation. Wheels include full thread guards to reduce debris entanglement. Recessed stainless axles are covered with plastic caps.