

Notify me
Price Match
If you find a lower advertised price (including shipping, handling and delivery) that is currently available on an identical branded item with the same features from a local retail competitor, compete this form and Enduro Sport will do our best to match that total price. Please read the complete conditions below.
The 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.