DIY Respirator box with HEPA + Carbon filter and oxygen mask with corrugated hose for example.
Box has variable dimension settings like OpenSCAD source file.
https://www.carmedia.cz/ohebna-hadice-husi-krk-30-35/
https://www.alfarescue.cz/kyslikove-masky-2/maska-kyslikova-pro-dospele/
https://www.alfarescue.cz/kyslikove-masky-2/maska-kyslikova-pro-deti/
PET-G, 0.2 mm
The author marked this model as their own original creation.