Anonymous ID: 7d879f April 17, 2020, 6:38 p.m. No.8832516   🗄️.is 🔗kun   >>2853

>>8832481

Those Inogen machines would also be easy to make cheap. Pressurized filtration through Zeolite, which removes Nitrogen from the air and increases oxygen concentration, then a one way blower valve to purge the nitrogen every breath.