This 6" x 2" Rubber on Steel Rigid Caster is an economically friendly option that provides decent resistance to shock and vibration, but is not recommended for environments where water or floor debris is present. It is also not recommended for delicate flooring, as it can leave marks when operated in less than ideal circumstances. Featuring a weight capacity of 550 lbs., the 80 Shore A black rubber is chemically bonded to a semi-steel wheel core and has an operating temperature range of -40° to +180° degrees Fahrenheit. Rubber on steel wheels provides good floor protection and quiet movement.
For more info, check out Caster Wheel Types.