The Shimano 105 ST-R7170-R is a right-side dual-control lever combining electronic shifting and hydraulic disc braking for road bikes. Unlike mechanical shifters, the Di2 system uses wireless electronic signals to control gear changes, eliminating the need for traditional shift cables. The lever features adjustable reach to customize the distance between handlebar and lever, a raised hood peak for ergonomics, and customizable button functions via the E-TUBE app. Battery life averages 3.5 to 4 years on two CR1632 batteries per lever. The lever is compatible with the full Shimano 105 Di2 R7150 drivetrain and can shift a 12-speed rear cassette paired with a 2-speed front derailleur. Weight is approximately 212g. Reach adjustment and ergonomic design make this suitable for riders with varying hand sizes and preferences, while wireless connectivity maintains a clean cockpit aesthetic.