Viruses cannot directly in the air, it KN95 Face Mask needs to be attached on the particulate matter, or droplets, is let's say the media such as dust, pollen, smoke. It can't fly, have to have a "spaceship" can free in the air. So we just defend it "spaceship", can isolate it outside the body. And their "spaceship", that is, those particles, we've said just now, the existing...