Service Caster 2 Polyurethane on Polyolefin Wheel Only with Roller Bearing

Listing is for one (1) Service Caster 4 inch diameter by 2 inch tread width Polyurethane tread on Polyolefin wheel with a roller bearing and 1/2 inch bore. Supports 500 pounds (lbs) per wheel. When searching for a reliable and durable solution for replacement wheels that are non-marking, smooth rolling, and quiet, consider Service Casters Polyurethane on Polyolefin core wheel. With a roller bearing with 1/2 inch bore for axle, Polyurethane is highly resistant to oil, grease, water, and most solvents. Non-marking polyurethane tread mechanically bonded to polyolefin core. Hardness scale 55 +/- 5 Shore (D) Durometer. An excellent choice for clean environments.