Black Bbb Rollerboys Ceramic Bearing Jockey Wheels 11T

11T Compatible for All Road/MTB Shimano 9 & 10 Speed / Mega Range Composite material supplied by EMS Swiss, with a 40% fiberglass blend that offers unmatched rigidity and precise displacement. All Bushings for Different Displacement Systems Are Included Equpped with Ceramic Bearings for Ultra Smooth Gliding and Almost No Resistance