Sram: The SRAM RED eTap rear derailleur executes shifts the instant you demand. Wirelessly. It's easy to set up, clean in appearance and delightfully uncomplicated. Mechanical necessities such as a carbon pulley cage, ceramic pulley bearings, and anodized alloy artfully blend with proprietary electronic advancements to deliver a shifting wonder.FEATURESSRAM eTap shift logic and wireless operationFits all 11-speed SRAM road cassettes up to 11-32t2x and 1x compatibleUpdated version of the original SRAM RED eTap rear derailleurOrbit chain management technology keeps drivetrain quiet and secureLarger X-SYNC pulleys and ceramic bearings for increased durability and efficiencyCompatible with existing eTap batterie SPECIFICATIONSSpeed (RD): 11sCable pull ratio: n/aCage (RD): ShortMax tooth: 33Color (RD): BlackPulley bearings material: CeramicCage material (RD): Carbon