Protective mask of class KN95. The mask is without an exhaust valve. Recommended use by the manufacturer for up to one week for daily use or up to two weeks for less frequent use. The mask must be exposed to direct sunlight every day for at least 15 minutes. In the absence of sunlight it can be exposed to direct radiation from a bactericidal UVC lamp. The mask is not washed or treated with detergents, if treated, it will violate the protective and permeable properties. After the recommended shelf life, it should be discarded.