I set this Systainer II up for my Dremel rotary tool , bits, and accessories. Did a little latch and handle swapping for a color coordinated look.
Cool thing about this is that the bottom part of the Dremel case fit in perfectly with only the rear corners needing to be notched (and lid removed). The Dremel with cutting wheel did the notches quick and easy.
It could also easily fit in a Sys- I , but I used a #II so that a lift out bit holding tray would also fit. The tray is a piece of MDF with two different holes sizes drilled. It has “feet” on the bottom edges to raise it enough to clear the Dremel underneath. The feet just sit on the edge of the Dremel case.
Holds a lot in an organized way and makes it easy to find and choose bits. I may swap the Systainer lid for the attic version to hold small boxed sets of bits.
If I add the flex shaft, and or want to hang the rotary tool, I would make a hook/stand similar to the one for the guns in my pneumatic Systainer. That would make a nice self-contained unit, and save searching for a spot to hang the rotary tool.