Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:3512833.

The tray that comes with dry erase boards cause markers to drop everywhere as soon as you want to have more than 2 color options.

Doesn't require any supports, could be printed shorter and still function just as well, so that's more aesthetics on how you want it to look.

For mounting markers are light enough that 2 or 3 wall strips seem to have held it up for over a year.