Sealed cartridge bearing (pair) 6001 (ID - 12 mm OD - 28 mm Width - 8 mm)Features:High quality steel cartridge bearings for a high quality repairWhere most bearings available after market are grade 300 (up to 3/10 of a millimetre out of round the equivalent of a human hair) Wheels Manufacturing produce a much higher grade steel bearing that's found in high-end Shimano and Campagnolo hubs and other high-grade componentsHeat treated steel races and sealed for longevityThese bearings increase the likelihood that your repairs have lasting quality resultsCome as a pair