Dura-Ace Di2: Instantly changing gear and minds. With Digital Integrated Intelligence the electronic Shimano Dura-Ace Di2 delivers state-of-the-art technology for a revolutionary road riding experience. Main items are the electronic rear and front derailleurs, powered by long-lived batteries, which offer extremely safe and fast gear shifting under all circumstances. The trained shifting patterns stay the same. Weather-induced influences like cold, wet and dirt are out of question. Impulse transition is effected by fly by wire. The road racing experience with the Shimano Dura-Ace Di2 is gorgeous.