5 колодки 3 слоя нетканые фильтра колодки для маски одноразовые маски pad рм2,5 пылезащитный прокладка замена

5 pads 3 layers non-woven disposable mask pad pm2.5 dustproof gasket replacement 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.