dhl ship2 1 pcs mask+ mask pad protective kids replaceable dust-proof breathable three-layer gasket

2 1 pcs mask+ mask pad protective gasket replaceable dust-proof breathable three-layer gasket v.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.