dhl ship isolation fine pm2.5 for replacement protective breathable pad replaceable anti dust mask

isolation fine mask pad for mask replacement protective breathable pad replaceable anti dust mask x.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.