In this period of general confusion there is no unanimity even on the masks. Which ones work? Which ones defend others and which ones ourselves? Here is a diagram that summarizes the characteristics and effectiveness of PPE, personal protective equipment, for mouth and nose. To learn more, read also: Coronavirus and 5G, Burioni asphalts the antenna conspiracy theorists With classic surgery, the wearer is potentially reached by 80% of dangerous particles. But the person wearing them does not infect others. Then there are those of the FFP category, able to stop the virus more decisively, but beware: not all are the same. Indeed, the differences in the degree of protection for us and for others are considerable. For example there is the FFp2 with filter. The wearer has an 18% chance of getting infected but 80% of infecting others if positive for the virus. With the filtered FFP3 there is a 5% chance of getting infected, but 80% the wearer can infect others if sick. The most effective protections would seem the FFp2 and FFp3 masks without filter or valve, in which the percentages of getting infected and infecting others are almost zero. But they are also the least easy to find but also to wear, as if worn correctly they make breathing difficult.