Shimano GRX RD-RX827-SGS Di2 Wireless Rear Derailleur - 12-Speed, Long Cage, Shadow ES, Black

The Shimano GRX RX827 Di2 Wireless rear derailleur paired with a 10-51t cassette (cassette sold separate) gives riders and racers the speed, range, and robustness to pursue any gravel challenge. With built-in automatic impact recovery, an impact-deflecting shape, and solid pulleys, this derailleur stands up to hard impacts and still retains its lightning-quick shifting performance.