Best Wishes for a Healthy~
-First layer of spunbond cloth filters micron-level dust-Second layer filters industrial pollutants, automobile exhaust, second-hand smoke, and pollen allergens-Third layer of activated carbon cloth filters micron-level dust-Fourth layer offers filter density for smaller material-Fifth layer of spunbond cloth filters out all kinds of harmful substances
-Made in China
Good price for masks and filters. Seem to work well. Quick delivery.Very satisfied.