What is a mask valve, and why are cities banning them?
In California’s Bay Area, there’s a new stipulation: You can wear any style of mask you want, so long as it doesn’t have a valve in it. What? Why? Because a mask with a valve may protect you from some pathogens in the air, but it doesn’t protect the people around you from your own breath.
Mask2.me proudly sells masks that do not have valves.