Shimano E-Tube wire holder pack of 20 For Di2 Frames, Re-Usable

does just the job;

They are easy to attach and feed through the wire entry port(s) in the frame. They're just as easy to pull out (carefully) if you happen to feed the wrong wire through part of the frame and have to replace it.;

So these are basically glorified zip ties that you out on the Di2 cables to help quiet them from rattling around inside your tubes. We’re they necessary probably not. I only used 6 on my install so I have plenty left for my next install. They have done their job to keep the cables quiet but then again I’m not sure how loud they would have been.;

" E-Tube wire holder pack of 20" is very useful parts for Di2 E-Tube Wire. If you use this holder with E-Tube wire. you can prevent to generate noisy and vibration sound which is generated in the bike frame. 4-5 holder are enough number for long (100mm) e-Tube wire. You also have the nice experience to make your bike noisy in the Frame without spending much money.
You have to keep the installation direction of this holder to the E-Tube wire. Check the user's Manual or Dealer's Manual.
Thanks;