Shimano SM-EW90-A Dura-Ace Di2 STI Stem Junction Box

Shimano SM-EW90-A Dura-Ace Di2 STI Handlebar Junction Box

Upgrading to one of Shimano's fantastic electronic groupsets, such as Dura-Ace 9150 and Ultegra 8050, is a fantastic choice and to do so you will require this Shimano SM-EW90-A Dura-Ace Di2 STI Handlebar Junction Box. This Junction box is used to connect the shifters via E-tube wires to the downtube junction wire. To accomplish this, a 3-port design is used with one for the downtube wire to bottom bracket junction and four for shifter connection. Shimano has made getting used to your new electronic gear shifting easier by incorporating a battery level indicator feature. Additionally, this junction box provides an alternative charging location for internal batteries.

As a final flourish, you can use this SM-EW90-A junction box for the gear index setup switch to allow fine-tuning via shifter buttons.

Please note, this junction box DOES come with a stem mounting strap, but NO E-tube EW-SD50 wires are included, but these are available separately.