activate pad carbon non filter dhl weave pm2.5 with individually packaged pads per box mask anti facemask

pm2.5 mask pad with individually packaged mask pads per box mask anti facemask 4.1.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.