filter activate dhl face cotton pm2.5 shipwashable for boy girl fashion breath valve mouth pad pollution activated

washable cotton famask for boy girl fashion breath valve mouth pad pollution activated carbon mask c.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.