pad allergies dhl anti-dust smoke faand ship9lhba adjustable reusable with pm2.5 activate wit9 1of04

9lhba anti-dust faand smoke pad allergies adjustable reusable with mask 2 dustproof was l.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.