Shimano Shimano Di2 E-Tube 4 Port Junction B - (SM-JC40 or SM-JC41) Colour:External make sure you're seen with

make sure you're seen with daytime visibility from more than 1 mile

It's up to you

Monitor your speed as you ride with the wireless Garmin Speed Sensor 2

replace chain at or just before the 0

boosts your muscle efficiency and accelerates your muscular regeneration

Shimano Shimano Di2 E-Tube 4 Port Junction B - (SM-JC40 or SM-JC41) Colour:External make sure you're seen withThe Shimano Di2 Junction B box is the center of the e tube Di2 system. All of the component and battery wires meet here before running out to their respective components. All of the wires that connect to the junction box use the same connector to make assembly that much easier. Choose the SM JC40 External box if you are running your wires on the exterior of the frame or choose the SM JC41 internal box if you are running your wires inside your frame.