Shimano Di2 Junction Box All Di2 components on the bicycle require the same firmware version. Using Di2 components with different firmware versions may cause malfunctions Use Di2 system checker to update component firmware from http://e-tubeproject.shimano.com/ SM-EW90-B 5-Port Cockpit Junction Box connects up to 2 pairs of Di2 shifters to the frame junction box via 5 SD50 E-tube wires OEM front wiring kit for Dura-Ace Di2 9070 LED battery charge level indicator Rear Derailleur adjustment mode Internal Battery charging port Includes Junction Box Band (CY9082) and Junction Box Hook (Mounting Plate, CY9081)