Respiratory protective masks, tightened around the mouth and nose and prevent the passage of particles of a specified size. N95 protective mask, which includes 6 layers of protection, filters at least 95 % of the particles in a size of 0.3 microns (And also most of the larger particles and many of the smaller ones). Used properly, these masks provide good protection against aerosol infection, so medical teams treating corona patients use them to perform medical procedures that increase the chance of aerosol formation, such as intubation (insertion of the soul tube) and bronchoscopy (examination of the bronchi).
Three-layer masks A three-layer mask made of non-woven cotton and covers the mouth and nose. Due to the diameter of the space between the mask fibers, this mask can block large drops and reduces hand contact with the mucous membranes of the mouth and nose, and therefore can reduce the chance of droplet infection on close contact. It also stops most saliva droplets emitted by patients and carriers, thus preventing them from infecting others.