NEW Shimano EW-JC304 Di2 Junction Box - 4 Ports, Use With EW-SD300 type_touring-bikes flat edges along their backs

flat edges along their backs to provide strong braking traction

Tubes: included and installed

plus an extra-wide PolyX breaker

but it still works with a normal freehub body and chain

it sets a new standard as ideal first pedal bike for children ages 3-7

NEW Shimano EW-JC304 Di2 Junction Box - 4 Ports, Use With EW-SD300 type_touring-bikes flat edges along their backsShimano 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