The Rival XPLR eTap AXS rear derailleur is a dedicated 1x-specific unit designed for use with the XPLR 10-44 cassetteWireless electronic eTap shift logic for intuitive shifting, easy setup and reliabilitySram AXS enabled, allowing easy personalizationChain management keeps the drivetrain quiet and secureLarger X-Sync pulleys with steel bearings for increased durability and efficiencyCompatible with existing eTap batteries - battery not includedRival XLPR12sp44BlackeTap AXSUPC/EAN/GTIN: 710845868993