Wireless Di2 shifting designed for E-MTB and HYPERGLIDE+. The ultra-durable RD-M8260 long-cage rear derailleur delivers features all riders can appreciate. It taps into proven wireless Di2 shifting technology and the strengths of other XT offerings while pulling power from the bike's main battery delivering a stable power supply and eliminating the need for a back-up battery.Direct Wired: The derailleur pulls power from your existing e-bike battery to deliver a constant supply of shiftsA wide link structure skid-plate design durable aluminum plate and solid pulley add robustness and longevitySHADOW ES: A slimmer stronger evolution of SHIMANO's pioneering chain-stabilizing SHADOW RD+ conceptE-Bike Technology: Intelligent AUTO SHIFT sensors and HYPERGLIDE+ technology provide smooth quick gear changes while you pedal so you are always in the right gearFREE SHIFT E-Bike Technology: Keep your speed and shift whenever. FREE SHIFT technology allows you to shift as you coast on flats or downhills