Shimano Dura-Ace/Ultegra Di2 SM-JC41 Internal Wire Junction Box 11.6115.530.060 Optimal mirror size of 73

Optimal mirror size of 73 x 67 mm for clear visibility

trail-taming RockShox suspension

ForkOrbea Terra ICR full carbon fork

2-millimetre version boasts a 3D forged construction with an AL6061 alloy lower and an AL7050 alloy shaft

Shimano Dura-Ace/Ultegra Di2 SM-JC41 Internal Wire Junction Box 11.6115.530.060 Optimal mirror size of 73This is the Shimano Ultegra Di2 Internal Junction Box. This box is referred to as the junction box "B" on a Di2 build. The SM JC41 is for use with internal wiring setups and is the main centre of e tube Di2 systems.. 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