Wireless Di2 shifting designed for E-MTB and HYPERGLIDE+. The ultra-durable RD-M8260 long-cage, 12-speed rear derailleur pairs best with the CS-M8200 10-51 cassette to deliver 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.