Purchased and never used.
-From SHIMANO's website:
SM-EW90-A 3-port Junction A mounts neatly to the bike stem and connects with E-TUBE wires from DI2 shifters and the downtube junction wire. The SM-EW90 junction box features an integrated battery level indicator, charging port, and gear index setup switch.
Ships only to continguous 48 states only (unless you want to inquire about extra shipping charges).
Keywords: Shimano Di2 Junction 3 Port E Tube E-tube Box Charging Port,