Shimano Di2 SM-EW90 Junction Box A Expand your secondary shift options with the Shimano Di2 SM-EW90 Junction Box. The junction box mounts directly below the handlebar, making wiring up a set of secondary shifters easy and making it all possible with minimal cabling. Available in a 3 or 5 port version, the SM-EW90 is the gateway to the ultimate Di2 expansion. Features: Expands Di2 systems to accomodate secondary shift buttons 3 or 5 port version Acts as a charging port for Shimano's internal SM-BTR2 Di2 battery (not included). | Shimano Di2 SM-Ew90 Junction Box A 3-Port