KOYO 6004 Open Deep Groove Ball Bearing 20mm x 42mm x 12mm

One of the most commonly used bearings, the open types are manufactured without seals to allow for the free circulation of either oil or grease, used in gearboxes and other environments where no foreign matter would be present and a lubricant supply is available.
Benefits: Used widely in transmissions etc, can be used in oil or greased, cost effective solution