original ply packed individually 3 pm2.5 fapm2.5 activate carbon filter replaceable mask pads per box d1ym

famask pm2.5 individually packed 3 ply mask pads per box q.1.the first layer: high efficient filter cloth filter the dust of micron.2.the second layer: meltblown cloth to filter industrial pollutants, automobile exhaust, second-hand smoke pollen allergies.3.the third layer: high efficient filter cloth filter benzene and a smaller function of filtering dust microns.4.the fourth layer: activated carbon cloth filter density, sma.