Bambu Lab Reusable Spool Saver

I love Bambu Lab filament refills, and I love the fact that I can print my own spools. Unfortunately, I have had a couple spools fail late in the print, and some spools lose the locking mechanism over time, so they are at risk of falling apart. And in one case I had a filament refill that didn't fit and I couldn't lock the spool halves together. Enter the Bambu Lab Reusable Spool Saver! It goes through the center of the spools and screws together, securely clamping the two halves of the reusable spool, so they can't separate and I don't have to throw away old, spools. The spool saver is compatible with the AMS. But the inner diameter of the spool is too small to put on the spool holder on the back of the Bambu Lab P1S. So with a spool that has a Bambu Lab Reusable Spool Saver on it, I use an external spool holder.