The Shimano ST-R8170 STI Shift/Brake Lever Left Hydraulic Di2 2 Speed is a high-performance component designed for cyclists who demand precision and reliability. With hydraulic braking for powerful stopping power and Di2 technology for seamless electronic shifting, this left lever controls 2 speeds for efficient gear changes. The ergonomic design ensures comfortable and intuitive use, making it an essential addition to any rider's setup.