защитная маска прокладка 3layer толстые рм2,5 фильтр рм2,5 activate углерода защитной вставки пыль замена pad площадь хлопок маска мат

protective mask gasket 3layer thick pm2.5 safety dust replacement pad square cotton mask mat.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.