OSPW for Shimano 9100/9150 and 8000 SS/8050 SS

The CeramicSpeed Oversized Pulley Wheel System for Shimano 9100/9150 and 8000 SS/8050 SS. The OSPW System has been proven to be the fastest pulley system in the world, providing energy savings starting from 2.4 watts over standard Shimano systems. Featuring a 13-tooth upper pulley wheel and a 19-tooth lower pulley wheel.