The respiratory valve seals during inhalation and opens slightly during exhalation. Lining and pocket provide two layers of filtration behind the valve.
Disposable carbon fiber filters add five additional layers of protection to limit bidirectional transmission of germs. Make sure you have enough.
- Low use (infrequently in public): Change every 1-2 weeks
- Medium use (briefly most days): Change weekly
- High use (multiple hours a day): Change daily for best protection
Replace filters that are folded, torn, or soiled. Shine a UV lamp (blacklight flashlight) on the mask and filter to detect presence of germs and bodily fluids. For hygienic reasons, masks are not returnable.