anti dhl pads pm2.5 shipmasques mascherina pollution 5 layer pm 2.5 dustproof core replacement mask only pad

masques mascherina pads 5 layer pm 2.5 dustproof mask core replacement mask only pad f.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.