SHIMANO Ultegra Di2 Internal Routing Junction Box
Brand: SHIMANO

Shimano's E-Tube Di2 Junction Box (also known as the B junction) connects all your component and battery wires to make assembly much easier. It's a crucial item along with the five required wire sections to operate your Ultegra 6770, Ultegra 6870, or Dura-Ace 9070 Di2 shift system. The E-Tube Di2 Junction Box is available in two configurations: Internal (SM-JC41) and External (SM-JC40).

Crankset Compatibility: 2 x 10
Compatible Components: Shimano Ultegra Di2
Recommended Use: ditching your mechanical tethers
Manufacturer Warranty: 2 years
Actual Weight Notes: Weight is for Di2 Junction B.