Your time on the bike is precious, let Shimano make it even better. Ultegra ST-R8170 brake levers bring enhanced modulation and control to every ride by employing Shimano's proven SERVO-WAVE technology. The Di2 platform untethers the shifters while delivering fast and reliable wireless shifting. The BR-R8170 hydraulic 2-piston disc brake caliper brings a new level of control to the road cycling world with improved modulation and a quicker initial braking point. Despite its smaller construction, the system is quieter than ever and easier to maintain.