DescriptionModel Number : R7000/R8000Total Capacity : 13/39TGears : 10 SpeedMaterial : Carbon FibreType : Rear DerailleurBrand Name : RacewoRKComponents : DerailleursSHIMANO R8000/R9100 R9150 SERIES:OSPW System for Shimano 9100/9150 and 8000 SS/8050 SSThe overall power savings of the OSPW System for Shimano 9100/9150 /8000 reach 30%-60%, or more in some cases, over a stock setup.The oversized pulley wheels have 3-5 times longer lifetime than the commonly used standard pulleys on the market.The Shimano 9100/9150 and 8000 SS/8050 SS OSPW system is compatible up to a 32 tooth cassette for both Dura Ace & Ultegra derailluers.Please note: The OSPW System for 9100/9150 and 8000 SS/8050 SS is NOT compatible with Ultegra 8000-GS or 8050-GS(medium cage) derailleurs, nor with the clutch equipped Ultegra RD RX800 & RX805.Pulley Wheels:Ceramic 13-tooth upper and 19-tooth lowerPulley Wheel Material:AluminiumBearing Options:Ceramic BearingCassette Compatibility:Fits 12 speed 10 to 36-tooth cassettes. For use with the 11 speed clutched derailleur fits 11-32 cassettes.Spring Tension Settings:2 springSpeed:12 speedDiscipline:Road and Gravel/Cross