shipbreathable pollution double single anti dhl pm2.5 valve air pad dust massk reusable noyc 2o7px

breathable single double valve air pad dust massk reusable 7.1.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.