Shimano 105 RD-R7150 Di2 12-Speed Rear Derailleur Black, Long, 12-Speed

Shimano brings its ultra-reliable electronic shifting to the masses with the 105 RD-R7150 Di2 12-Speed Rear Derailleur. Pulling together all of the features we've come to love from their Dura-Ace and Ultegra Di2 road cycling systems, Shimano has created a low-profile rear derailleur that we can rely on at a budget-friendly price point.