Basic knowledge of masks all we should know
Masks (hygiene items used to filter air entering the nose and mouth) Edit Discussion 99+ Upload video Respirator is a kind of hygiene products, generally refers to the mouth and nose is used to filter the air into the nose and mouth, in order to achieve the role of blocking harmful gases, odors, droplets, viruses and other substances, made of gauze or paper. Masks have a certain filtering effect