KN95 mask is a Chinese standard mask derived from Chinese national standard GB 2626-2006 "Respiratory protective equipment self-priming filter anti-particulate respirator".
"KN" indicates that it is used to protect non-oily particulate matter (such as viruses, bacteria, dust, etc.); "95" indicates that the filtration efficiency of the mask is ≥ 95% under the detection conditions specified in the standard. The KN95 mask is effective for particulate matter suspended in the air protection.