Listing is for a set of four (4) Service Caster Series #30 casters with a 8" diameter, 2" wide thermoplastic rubber donut tread on polyolefin core wheels. Set includes two (2) swivel casters and two (2) rigid casters. Supports 2400 total pounds (lbs) at 600 pounds (lbs) per caster.When searching for a reliable and durable solution for medium and heavy duty projects, consider Service Caster's Series 30 top plate thermoplastic rubber donut tread on polyolefin core casters. The rounded face "donut" style soft tread is made of thermoplastic rubber that is non-marking, non-marring and provides easier mobility over standard flat tread wheels, resulting in a long lasting, high capacity wheel capable of easy rolling under heavy loads. Finely crafted with double ball bearing heat treated raceways, 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.