3M9001 mask belongs to 3M KN90 series masks, although the protection effect is not as good as N95 or KN95 series, but it can also be used to protect against new coronavirus infection. First of all, the new coronavirus is mainly transmitted through droplets, and bringing this mask can effectively block the droplets. Secondly, 3M KN90 series masks represent an interception efficiency of 90% for 0.3 micron particles, and there is no problem to isolate viruses. Although the KN95 series filtration efficiency is 95%, the effect is a little better, but currently expensive and can not be purchased, so when out shopping, walking is completely replaceable with KN90. However, if you go to crowded, non-ventilated places, try to wear N95, KN95, medical surgical masks or medical protective masks.