They are rubber sealed ball bearings, that provide smooth rotation, great accuracy of accessory and also simplified maintenance.
• 840 Sealed Ball Bearings x2
• Applications include TA07 framework pulleys, and M-chassis countertop gear area.
• making use of ball bearings instead of synthetic and metal bearings offers better parts fit and much more efficient rotation.
• These ball bearings use plastic seals instead of metal people – this permits one to open them up to neat and work with them.
• Low-friction oil is used to lubricate the internal workings.