The next generation is here. Evolution never stops! With Ultegra Di2 technology shifting is easy and precise. Taking shifting to a new level, only a light touch is needed for the front or rear derailleur to instantaneously select the correct gear. Ergonomic design ensures an easy transition from mechanical to electronic shifting, and you'll never look back. This drop handlebar cable set is required to connect the shifters to the included battery indicator junction box controller. The removal of traditional mechanical cables in favour of electrical wires not only eliminates poor shifting caused by contaminates, corrosion and stretching, but gives effortless gear shifts.