layer 81ch child pads original 5 insert protective mat mouth replaceable s pad pm2.5 acti hhvf

81ch layer 5 child pads insert protective mat mouth replaceable s pm2.5 mask pad mma3365 cloth face 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.