These are rubber sealed ball bearings, which offer smooth rotation, great precision of attachment and even simplified maintenance.
- 630 Sealed Ball Bearings x2
- Applications include touring car belt tensioners.
- Using ball bearings in place of plastic and metal bearings gives better parts fit and more efficient rotation.
- These ball bearings employ rubber seals rather than metal ones – this allows you to open up the bearings to clean and work on them.
- Low-friction oil is used to lubricate the internal workings. | 
