Pylon Container (Crystal/Barrel Dice Box)
Pylon because it reminded me of Pylons... It was designed to hold Barrel/Crystal dice from Crystal Caste, or at least my set.
Do note that I included two versions, the pictured version that I added magnets to is scaled to 115%. The original size held a small D20 and the crystal dice except D20.
The little hole is designed so you can push up a normal D20 or other die so you can remove it without the dice just spinning around. It's ultimately what I settled with, and I recommend you experiment/modify it to find a solution that works for you.
With the little holes, the barrel D20 does stick out a tad if you don't raise the scale it enough for the D20 to fit inside of the container. I personally prefer using a normal D20 though, as it's easier to read and can rest inside of the container to show the roll.