Initiative Tracker for 3/4" (19.05 mm) GM screen

This thing was made with Tinkercad. Edit it online https://www.tinkercad.com/things/grLrr18koMR

I'm building my own GM screen out of wood and i wanted to make some custom initiative trackers for it so that's what these are. I plan on putting magnets in the top's so i put a small whole there for that reason. the should measure 2' long by 3/4 wide by 1' high give or take i made 1-20 plus one blank one for testing purpose's so this is a work in progress i may be changing this in the future and m