This junction A is required to connect the shifters via E-tube wires to the down tube junction wire. Gear index setup switch to allow fine tuning via shifter buttons.
Shimano Non-Series Di2 Di2 EW-SD300 E-tube Di2 Electric Wire
Shimano Non-Series Di2 Di2 EW-AD305 SD300 to SD50 Conversion Adapter
Shimano Non-Series Di2 Di2 EW-JC304 SD300 4 Port Junction
Shimano Non-Series Di2 EW-WU111 E-Tube Di2 Wireless Unit, 2 Port
Shimano Non-Series Di2 TL-EW02 E-Tube Di2 Plug Tool
