For the DURA-ACE Di2 9170 series, Shimano has redeveloped every single system component to create the most innovative component group of all time. The ST-R9170 dual-control lever for hydraulic disc brakes offers a shorter stroke and a wider adjustment range with more reach. This facilitates switching operations for fast and intuitive switching in all situations. The precise pressure point of the circuit ensures that shifts are triggered only when the driver switches consciously. Accidental switching is not to be feared. The more defined click gives you the feeling of more control every time you shift. Synchronized Shift gives you more efficient gear changes while driving. The function offers numerous advantages such as faster, more precise gearshifts under all driving conditions and minimizes the load on the drive. The switching logic can be customized. This allows Multi Switch to be switched on or off for each switch. In addition, the keys on the top cover can be programmed for third-party control. With the E-Tube app or the Shimano PC software, all functions are customizable. Combined with the hydraulic Dura Ace disc brake, the Di2 lever offers high braking performance and control in all conditions.