Masks act as a filtering barrier to protect our respiratory system and are effective in preventing infectious diseases. It is necessary to choose the mask reasonably and wear it correctly. At present, the mask on the market is mainly divided into three categories, one is the filtration efficiency of the lower cotton mask; one is a slightly higher filtration efficiency, non-woven disposable medical masks; one is the filtration efficiency of the higher protective masks. cotton mask A mechanical filter mask that acts as a filter through layers of cotton. Cotton masks have the lowest filtration efficiency and can only have some blocking effect on coarse particles like hair strands, but they provide the best warmth and comfort. disposable mask It is mainly made of non-woven fabric and has a slightly higher filtering effect than cotton masks. Medical masks without the word "protection" on the name of the "surgical" are the ordinary level of single-use medica