They are rubber sealed ball bearings, which offer smooth rotation, great accuracy of accessory as well as simplified maintenance.
• 630 Sealed Ball Bearings x2
• Applications include touring automobile gear tensioners.
• making use of ball bearings in the place of synthetic and steel bearings gives better parts fit and much more efficient rotation.
• These ball bearings use plastic seals instead of metal people – this allows one to start the bearings to clean and work on them.
• Low-friction oil is employed to lubricate the inner workings.