The KN95 mask With filter, breathing valve is one of nine particulate protective masks. "N" means not resistant to oil. "95" indicates that the particle concentration in the mask is more than 95% lower than that of the particles outside the mask when exposed to the specified number of special test particles. The 95% value is not the average value, but the minimum value. N95 is not a specific product name, as long as it meets the N95 standard and passes the NIOSH review, it can be called "N95 mask". The protection level is N95, which means that under the detection conditions specified by the NIOSH standard, the filtering efficiency of the mask filter material for non-oily particulate matter (such as dust, acid mist, paint mist, microorganisms, etc.) reaches 95%