Clean Cockpit: Wireless connection enhances the aesthetic of your bike while keeping shifting lightning fast 1.5 to 2 years of battery life with easy-to-change CR1632 shifter batteries 10% wider pad clearance decreases the chance of rotor rub Unparalleled ergonomics engineering refined with pro rider feedback Raised hood peak improves ergonomics, while a longer hood body increases hand support Taking their already excellent disc brake technology to the next level, Shimano's Dura-Ace St-R270 brake levers use servo wave action to provide even better modulation and control. With 12-speed Di2 wireless shifting, these shifters push the envelope of bike technology. The BR-R9270 disc brake caliper completes the package with increased pad clearance to help keep the brakes quiet.