The revolutionary Dura-Ace Di2 electronic shifting option with SEIS (Shimano Electronic Intelligent System) takes the already superior Shimano shifting performance to a whole new level never seen before. The increased accuracy, smoothness and reliability of electronic shifting makes gear changes faster and virtually eliminates missed shifts.

Dura-Ace DI2 takes Shimano shifting performance to a whole new level with SEIS (Shimano Electronic Intelligent System). In addition to uni-directional carbon fiber levers, the electronic shifters are ultra lightweight & Flight Deck compatible with a wireless speed sensor that allows for intuitive operation without changing hand position.

The front derailleur: contains the shifting logic and enables the shifters to stay in constant communication with the whole system. Front shifting is the most perfect front shift available today. With automatic micro-trim adjustments, the chain is kept perfectly aligned and quiet.

Battery: At a feather light 71g, the DI2 battery pack powers your entire system. On average, the battery can hold a charge for 1000 miles. Your current battery charge level can be checked through the front wire kit. The rear wire kit is built into the battery cradle mount and is needed to operate your respective system.

Rear derailleur: Through SEIS, the electronic rear derailleur is the fastest & most precise shifting available for the road. In addition, the carbon pulley plate is lightweight and rigid while adding a dash of style.