They're plastic sealed ball bearings, which offer smooth rotation, great accuracy of accessory and also simplified maintenance.
• 630 Sealed Ball Bearings x2
• Applications include touring vehicle belt tensioners.
• Using ball bearings instead of plastic and metal bearings gives better components fit and much more efficient rotation.
• These ball bearings use plastic seals instead of metal people – this permits you to definitely open the bearings to clean and work on them.
• Low-friction oil is used to lubricate the interior workings.