The Chris King PressFit 30mm Ceramic bottom bracket brings smoothness, reliability, and quality to PF30 equipped frames. Both cups house 24 ceramic balls in each cartridge providing a measurable reduction in friction and weight when compared to steel. That means you'll be riding faster. Bearings are user serviceable with King's Grease Injection Tool available separately. Just add fresh grease to purge the gunky, used grease and keep spinning. Racers can run thin grease or even oil on race day to minimize bearing drag and switch back to thicker grease for training to maximize the lifetime of your bearings.