An open bearing means that no sealing rings are used on both sides of the bearing, and the internal structure of the steel ball and retainer can be clearly observed. This requirement is necessary for most use conditions. Its main function is to isolate the external pollution source and create a barrier, so that the necessary grease between the rolling element and the groove track is sealed, so that the grease has storage space and avoids rapid loss, sealing The ring is a very important contributor to the bearing life factor. The material of the sealing ring is mainly iron or rubber-coated steel sheet. We have designed a variety of contact types for the movable end to find a balance between the isolation effect and the friction coefficient. There are many exclusive modes for different external use conditions.