washable pm2.5 original activated with carbon dust faface pm 2.5 s air face filter pad mask m4og

famask washable pad pm2.5 with activated carbon dust pm 2.5 s air mask n.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.