Shimano SM-EW90-B 5 Port Junction A

When setting up your Di2 electronic shifting for road or TT/Tri bikes, you have the option of connecting up to four shifters. For road these may be the standard Dual Control with sprinter or climber locations for satellite shift buttons. For TT/Tri you can use aerobar end buttons as well as those located on the brake levers. A total of four shifting wire ports covers those choices, and the fifth port is to attach the downtube port connecting wire. The under-stem mounted Di2 E-Tube SM-EW90A-B 5-Port Junction Box also features an integrated battery level indicator, charging port, and gear index setup switch.Details Di2 5-port junction used when Di2 shifters via e-Tube wiring system One to four shifters can plugged in, plus the wire that connects to downtube junction LED battery charge level indicator Gear index setup switch Internal battery charging port Normally used for road bar set-ups with satellite buttons or TT/Tri aerobar controls Mounts under the stem via curved mount plate with strap ties Shimano part # ISMEW90BAll Di2 components on the bicycle require the same firmware version. Using Di2 components with different firmware versions may cause malfunctions.

On some time trial/triathlon bikes this can be mounted internally.