Made this for my own dice collection, Use the small ¼" 1/16" magnets to snap the box together and into the tray, Carry it to your game and setup. Tray is designed to take a sheet of foam on the bottom.

I just updated the files to align the magnets better in the tray, and gave an alternative top.

I added a new design based a octagon. Center circle for a mini and two spaces per die type.