Experience a better bike ride. The SRAM Rival eTap AXS 12-Speed Rear Derailleur features the technology modern riders demandintuitive wireless shifting, innovative gearing, integrated power measurement, AXS connectivity, and refined hydraulic disc brakes. Its low on complexity, but rich with features.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.Key Features:Wireless electronic eTap shift logic for intuitive shifting, easy setup, and reliabilityCompatible with both 1x and 2x drivetrains36T cog max derailleur works with 10-28T, 10-30T, 10-33T, and 10-36T cassettesSRAM AXS enabled, allowing easy personalizationSpring clutch keeps the drivetrain quiet and secureX-SYNC pulleys for increased durability and efficiency Please note: Derailleur doesn't include a battery.