Listing is for a set of four (4) Service Caster Series #30 casters, two (2) swivel casters with side lock brakes & bolt on swivel locks and two (2) rigid casters, with 4" diameter by 2" wide polyurethane tread set on a polyolefin core wheel and maintenance free precision ball wheel bearings capable of supporting a total weight of 2,400 lbs. (600 lbs./caster). When searching for a reliable and durable solution to your caster needs, consider Service Caster Series 30 polyurethane wheel casters. The Service Caster Series #30 features heavy duty non-marking polyurethane tread on a polyolefin core wheel, providing a smooth roll over uneven surfaces without marking or marring floors. These versatile casters are ideal for a wide range of applications, such as dollies, platform trucks, warehouse carts and freight terminals. Or ensure a smooth and secure ride for food service carts, hotel housekeeping carts, and industrial and commercial equipment. Even drywall carts, welding carts, and wall panel carts will be ready to roll on the Series 30, keeping you moving forward. Service Caster is unsurpassed in quality, reliability, and excellent customer service. Count on us to move you forward.