Shimano SM-JC41 DI2 INTERNAL JUNCTION BOX

Frame Junction Box connects via SD50 E-tube wires to four different points: front derailleur, rear derailleur, cockpit junction box and battery mount.

All Di2 components require the same firmware version.

Using Di2 components with different firmware versions may cause malfunctions.

Shimano Di2 Junction Box Junction Box UPC: 689228827462