Inspired by https://www.thingiverse.com/thing:4689265.
Additionally extended for ruler, brush and calipers. Unlike the original version, this designed for rear placement (next to ender 3 v2 display on the same side). Added small lockers on the rails, so it's fit tight - be careful during installation and not smash it. Nothing really special in terms of printing. It optimized for filament consumption, all "fat" ceilings are hollow. I used PETG but it could be any filament for your choice (not sure about flex filaments, but if you will get success with it, please share your experience in the comments). Vertical print with no supports, rafts or other stuffs like this