dhl shippm2.5 mask filter activate carbon gasket three layers safety dust-proof breathable mouth face mask replacement pad l116fa

gasket three layers safety dust-proof breathable mouth famask replacement pad pad l116fa r.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.