Non-medical masks cannot stop the new coronavirus, let alone prevent the infection of the new coronavirus. Non-medical masks are those sponge masks, cotton gauze masks and activated carbon masks. These ordinary masks are not made of fine enough material and have large surface gaps and no filtering layer, which cannot effectively stop new coronaviruses and droplets containing viruses. Because the diameter of virus-containing droplets is mostly around 5 μm, and in the case of new coronaviruses the diameter is even smaller, these viruses and droplets can easily penetrate ordinary coughs and become infectious. Clinically, disposable medical surgical masks or N95 masks are usually used, and sometimes N90 and N99 masks can also be used, which can effectively stop or filter droplets containing viruses.