3 ms·
> It only filters on the way in. Absolutely not? How would that even work. A well-fitting half-face mask has virtually no leakage when breathing in or out.
by fuzzy2 5y ago
> It only filters on the way in.
Absolutely not? How would that even work. A well-fitting half-face mask has virtually no leakage when breathing in or out.
- parkingrift 5y agoYes, thank you. I had incorrect information and edited my post.