XT Shadow ES 12-speed wireless rear derailleur for the ultimate in shifting performance and durability.The integrated removable on-board battery is protected within the linkage, Crash recovery function, absorbs impacts and returns to its original positionConnectivity BLE, ANT privateShadow ES features a super low profile skid plate design and optimized slant angle for optimal clearanceShadow ES uses a dual spring chain stabilising switch that when on will reduce chain bounce in rough terrain maintaining more stable drive and shiftingThe Shadow ES system is also zero maintenance and has no degradation of performance.Unique structure using two springs has a tighter chain wrap that improves shifting and security with increased spring force by 70%, allowing the chain to mesh firmly with the sprocketWith the tighter chain wrap skipping is prevented even as the cogs wear, shifting can now happen as quickly and effortlessly as possible thanks to ergonomic 4-way multi adjustable short stroke p