SRAM Force AXS eTap Rear Derailleur - 12-Speed Medium Cage 36t Max (Battery Not Included) Iridescent Gray D2. The SRAM Force AXS rear derailleur features a single cage length that works with any cassette size from 10-28T to 10-36T in 1x or 2x configurations. Shifts are fast and precise and the Orbit fluid damper keeps the chain in control whether the obstacle you’re hitting is a pothole or a root. Wireless and proven eTap shift logic AXS connectivity and advanced chain management mean this derailleur does exactly what you want when you need it.Orbit chain management technology keeps the drivetrain quiet and secureAXS enabled for easy setup personalization and reliabilityCompatible with both 1x and 2x drivetrains36T-max derailleur is compatible with cassettes with big cogs from 28T to 36TeTap shift logic for intuitive shiftingLarge X-SYNC pulleys for increased durability and efficiency.