http://www.bocabearings.com/productd...SubGroupID=139 Kit Number : #MCK-067C-RS/C3 #3
Kit Type : Ceramic Lightning Yellow Seal Motorcycle Wheel Bearings
Description : Ceramic Lightning Yellow Seal Motorcycle Wheel Bearing Kits are specially designed for off-road or excessively dirty operating environments. These bearings are maintenance free and lubed for life. The heavy duty rubber seal provides extra protection against the harshest elements. Ceramic Lightning bearings have ceramic balls, with stainless steel races and retainers. Ceramic hybrids are lighter, capable of achieving higher RPM’s and sustaining higher operating temperatures than traditional bearings. Bearings that are packed in grease will require a short break in period to loosen up. Grease can usually be removed before shipping upon request. Please contact Boca Bearings directly before installing ceramic bearings in a motorcycle engine.