Many people have heard that wearing a N95 or KN95 medical mask provides a reliable protective effect during the COVID-19 pandemic. KN95 masks are a respiratory protective device designed to provide a very tight fit to the skin of the face and effectively filter out airborne particles, including bacterial ones. Thanks to the inner filtering layer made of non-woven polypropylene fiber, they are able to filter out up to 95% of dangerous particles of 0.3 microns in size: dust, moisture drops, vapors. Blocks the body fluids of the mask wearer from getting to others, for example, when coughing or sneezing. At the same time, the negative influence of small aerosol particles coming from outside is reduced. The duration of wearing is about 6-8, and in some cases up to 10 hours, instead of 2-3, as with conventional disposable masks. But in both, it is not recommended to reuse the protection tool. Due to their functional characteristics, these respirators are used by health care workers who have direct contact with patients suspected of being infected or already infected. In a domestic environment, they have also proven themselves as a reliable means of protection and are trusted by users.