NEW Shimano SM-JC41 Di2 Internal Frame Junction Box 4-Port frontder_2x runs quieter and further improves

runs quieter and further improves chain retention

Shot-peened finish

5mm thick (compared to the 5mm of Supple Bar tape)

Proprietary ZSG (Zero Slip Grip) natural compound

Shimano Dura-Ace BB92

NEW Shimano SM-JC41 Di2 Internal Frame Junction Box 4-Port frontder_2x runs quieter and further improvesShimano Di2 Frame 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 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