The SRAM RED eTap AXS rear derailleur is AXS enabled for easy personalization and designed for both 1x and 2x systems. Orbit advanced chain management technology keeps it silent and secure no matter the terrain. Component upgrades include faster pulleys, bearings, motors and signals, to improve speed in every way.-Battery sold separately-SRAM AXS enabled for easy personalization-Orbit chain management technology keeps drivetrain quiet and secure-Shifting is optimized with an advanced motor and signal travel-Large X-SYNC pulleys and ceramic bearings for increased durability and efficiency-Compatible with existing eTap batteries