Well, if you know why you would need this, then you know it's a necessary piece of equipment for your bicycle updates arsenal. (If not, you probably are not going to buy this item). So, needless to say, it is a fair deal. It's simple to use and if you have any doubt. there are many sites on-line that can help with written instructions and/or videos.
Used this long cable to perform the left and right Di2 shifter updates on latest 12spd system. Flawless
Long enough from rear derailleur to shifter to update firmware.
these are really thin now. connection is like before, but with a new version of the insert tool. you just have to run wires between the front and rear mechs and up to the seat post battery. I used 650 & 1200 (58 cm frame) and still ended up with 10 cm of extra out the top. just coiled and push back down into the seat tube. works fine.
