The Shimano E Tube Cockpit Junction Box works with the Dura Ace Di2 9070 groupset to enable supplemental shifting positions so that the ease of electronic shifting is always at your fingertips, no matter what hand position you favor. The E Tube mounts just below your handlebars and functions as a junction box so that no additional wiring is needed to add a second set of shifters to your bars. Now you can keep your hands in the drops to maximize aerodynamics on long, flat stretches and up high for greater control. And for even more options, the E Tube Cockpit Junction Box comes in two configurations: a three port and five port. To keep you running, both versions feature a charging port for the new internal Di2 battery.