N95 is one of the levels specified in the American standard 42CFR84, and KN95 is one of the levels specified in the Chinese standard GB2626-2006. There is no difference in the protection effect of the two, both have a filtration efficiency of 95% for 0.3 micron non-oily particles, but the code is different. Before wearing n95 and kn95 masks, wash your hands first, and avoid touching the inner side of the mask
with your hands during the process of wearing the mask to reduce the possibility of contamination of the mask.
Distinguish the inside, outside, top and bottom of the mask: the side with words is the outside, and the end with a metal strip or sponge strip is above the mask. Do not squeeze the mask with your hands to prevent the virus from penetrating into the inlet mask with droplets and causing virus infection. In normal use, it is generally sufficient to replace it once within 4 hours. If it is replaced too long, the mask will lose its proper function.