2020 stock activated replaceable 5-layer shippingin carbon s of dust-proof mask pm2.5 ant l1w2

in stock 2020 5-layer activated carbon replaceable s of dust-proof mask pm2.5 anti haze fareplacement pads f.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.