spool holder

Here is another spool holder. The advantage from this one is that you can place them on each other. When you place your holders like me, you can stack 3 spools on each other. If you work vertically you can do as manny as you need.
I make 2 types one for 1.75 and one for 3mm. I also make 2 lengths of spool holder. So take the one you think fit best.
The diameter off the holder is 50mm?
Normally the holders fits nice together but my experience is that not every printer print the same so you n