The Shimano 105 Di2 rear disc brake set pairs the ST-R7170 right shift/brake lever with a BR-R7170 flat-mount hydraulic caliper.

• Right ST-R7170 Di2 lever with rear BR-R7170 caliper
• Wireless 12-speed Di2 shifting; two CR1632 batteries, approx. 3.5-4 years life
• Flat-mount caliper with L05A-RF finned resin pads
• 10% wider pad clearance to reduce rotor rub
• One-Way Bleeding and lever reach adjustment
• 1700 mm cuttable hose (SM-BH90-JK-SSR)