About this 3D model
How to torn ventilation mask to a filtration mask with a HEPA filter The instructions are in the PDF it takes about 2h to print at 0.1mm accuracy. Safety concerns: It's not easy to Breathe throw, I wore it for about 40 minutes and felt a bit dizzy. If you keep the filter spread apart it's more easy to breath. Your first instinct will be to take dep breathes you should try to stop yourself and breath throw the nose and slowly. Instruction V2: I have add a new Valve that is easier to breathe throw.