100% Brand New with High Quality Spindle Interface Type: , Hollowgram SI / SL / Compact For Bike Type: Time Trial Triathlon, Cruiser, Cyclocross Bike, Dirt Jumper, Folding Bike, Mountain Bike, Recumbent Bike, Road Bike - Racing, Road Bike - Touring, Bike , Track Bike, Tricycle, Unicycle, Bike - Fixed Gear . Self-lubricating ceramic ball self-lubricating with self-lubricating properties prevent the lubrication of ceramic ball bearings Insulation, rolling body with ceramic ball, you can achieve the bearing between the inner and outer ring insulation High speed, the use of ceramic ball speed compared to the general bearing speed is much higher Long service life, ordinary bearings in the and high temperature environment, the is easy to wash or kill, so that the bearings quickly become bad, the use of ceramic balls as rolling body, do not worry about any problems. Waterproof: Normal bearings used in the, grease degreasing, the bearings soon broken, the use of ceramic balls, that you can