The SRAM RED eTap AXS rear derailleur is designed for both 1x and 2x systems and is AXS enabled for easy personalization. It includes advanced Orbit chain management technology to ensure a quiet and secure drivetrain regardless of terrain. The derailleur has faster pulleys, bearings, motors, and signals to improve speed. The product is compatible with existing eTap batteries, but the battery is sold separately. The derailleur also has large X-SYNC pulleys and ceramic bearings to increase durability and efficiency.