On any surface you can imagine, in any drivetrain configuration, the rival etap axs rear derailleur will handle it. Secure chain management and fast, precise shifting make for a smooth and quiet ride, every time.Featureswireless electronic etap shift logic for intuitive shifting, easy setup and reliabilitycompatible with both 1x and 2x drivetrains36t cog max derailleur works with 10-28, 10-30, 10-33, and 10-36 cassettessram axs™ enabled, allowing easy personalizationchain management keeps the drivetrain quiet and securex-sync pulleys for increased durability and efficiencySpecificationsspeed (rd): 12scable pull ratio: n/acage (rd): n/amax tooth: 36color (rd): blackpulley bearings material: steelcage material (rd): aluminum