Shimano 105 Di2 R7150 R7170 Disc 12 Speed Electronic Disc Partial Group set
ST-R7570 SHIFTERS ELECTRONIC DI2 2 X 12 SPEED FOR DISC BRAKES Wireless (communicate with Rear Derailleur). - RD-R7150 Di2 Rear Derailleur (brain of the group, communicate with shifters wireless - NO charging cable included).