KN means the mask is suitable for filtering non-oily particles. The larger the number, the higher the protection level.
Only after the test and certification are obtained, there is a KN95 and other protection level certification report.
The identification of fine particles reaching more than 90% of shielding is KN90,
Identification of fine particles that reach more than 95% of shielding is KN95
KN100 was identified as a fine particle that achieved shielding above 99.97%.