The Sram Red ETap Short Cage 11 Speed Rear Derailleur allows you to execute shifts quickly and precisely. The eTap derailleur features Airea™ and Exact Actuation™ technology to stabilise hangar design, tight cog spacing and cable tension for easy set-up and shifting security. eTap technology has been designed for intuitive and consistent shifting, and the SRAM RED eTap Rear Derailleur Short Cage 11-Speed will ensure all your shifts are precise and instant. The design has a smart, clean appearance and fuses electronic technological advancements with a carbon pulley cage, ceramic pulley bearings, and anodised alloy.  Sram Red ETap Short Cage 11 Speed Rear Derailleur Features Speeds: 11-speed Weight: 239g (with battery) Outer cage: carbon Compatibility: SRAM RED eTap, PowerdomeX & PowerGlide cassettes Inner cage: carbon Finish: black Max tooth: 28t Pulleys: ceramic Pull: Exact Actuation Technology highlight(s): eTap, AIREA