OSPW X for Shimano GRX 2x12

This 13-tooth upper and 19-tooth lower OSPW System has been platform proven at races like Paris-Roubaix, Strade Bianche and CX World Cups. Built for gravel and cross disciplines with carbon fiber cage. CeramicSpeed OSPW Systems reduces friction 35-40% over stock pulley configuration. Compatible with Shimano GRX RX820/RX825 derailleurs.