dhl shipchild 5 layers pad 5ply pm2.5 mask activate filter activated carbon for dustproof cotton mouth muffle

child 5 layers pm2.5 pad 5ply activated carbon for dustproof cotton mouth muffle g.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.