ZTTO 12T Bicycle Rear Derailleur MTB Road Bike Ceramic Bearing Pulley Jockey Wheel Guide 4mm 5mm 6mm Roller Idler Parts Golden

Description

All the results of the simulations and the experimentations indicated that the ceramic ball bearings' performances are very good, especially in the low load and high-speed environment. Fit for 4/5/6 MM roller screw axis. Apply for most of rear derailleur on the market .