dhl ship individually packed filter pad for north by peel-away pm2.5 mask pads per box

individually packed north by peel-away mask pads pm2.5 mask pads per box w.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.