CeramicSpeed's OSPW RS System for Shimano Road Dura-Ace R9250 and Ultegra R8150 has been lifted with a distinctly modern and angular design. The updated design brings balance and refinement to the OSPW System allowing it to blend seamlessly into the contemporary design trends of bikes and groupsets - making up the whole of which the OSPW RS System is part. Innovative tech features of the OSPW RS meets consumer demands for a premium ride experience. The design for the OSPW RS isn't solely a visual update. The cage itself has been reinforced to offer new levels of strength and durability. The CeramicSpeed OSPW RS System continues the tradition of providing optimization and increased efficiency of the rear derailleur through its extremely low-friction bearings and unique overall design.Injection Molded Carbon Fiber reinforced PA cage offers new levels of strength and durabilityPremium 3D printed hollow titanium 13-tooth upper and 19-tooth lower pulley wheels are exceptionally light weight and incredibly durable and feature an oil slick PVD coating for added protection with great looksThis OSPW System has handbuilt CeramicSpeed coated bearings installed in each pulleyGrade 3 Silicon Nitride ball bearings are 400% smoother, 128% harder and 58% lighter than standard steel balls normally used in the bicycle industry4 customizable spring tension settings for optimal setupCompatible with Shimano Road Dura-Ace R9250 and Ultegra R8150 12-speed rear derailleursItem SpecificationsDefined ColorBlackDefined ColorMulti-ColorDrivetrain Speeds12Fits BrandShimanoFits ModelDura-Ace R9250Fits ModelUltegra 8153Largest Cog34 CeramicSpeed OSPW RS Pulley Wheel System for Shimano Dura-Ace 9250/Ultegra 8150 Cage Assembly