The EW-SD50 E-Tube Wires are the circulatory system of the Ultegra 6770 and Dura-Ace 9070 groupsets.
You'll need four of these to connect the Front Wire/Junction (A) to the Rear Junction Box (B), Battery, Front and Rear Derailleurs (all sold separately). Dura-Ace requires two additional wires because the shifter control wires are not integrated into Front Junction Box (A) as they are with Ultegra. So that makes six total for Dura-Ace 9070 groups, and four total for Ultegra 6770 set ups.
E-Tube wires come in a wide variety of lengths to accommodate every bike out there (tandems too). If you end up with a wire that's slightly too long, it's possible to remove a few cm of slack at the junction box.
The Di2 EW-SD50 E-Tube Wires are sold individually and are compatible with internally or externally routed systems. The SM-GM01 and SM-GM02 Rubber Grommets are recommended for frames with internal cable routing. For external routing, add the SM-EWC2 Wire Covers for a sleek look.
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