анти пыли двойной дыхательный клапан маски мягкий открытый губка рот маска pad pm2.5 черный

set replaceable disposable mask gaskets pads 3 layers anti-dust waterproof breathable face mouth paper features: 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.