1. Five layers of protection. 2. With breathing valve. 3. The first layer: 50 grams of non-woven fabric, the second layer: 25 grams of hot air cotton; the third layer: 25 grams of 99% melt-blown fabric; the fourth layer: 25 grams of 99% melt-blown fabric; The fifth layer: 25 grams of non-woven fabric. 4. Optional internal and external nose bridge. 5. Complete export qualifications, with CE, FDA certificates.
