KN95 mask has a filtration efficiency of more than 95% for particles with an aerodynamic diameter of 0.075µm±0.02µm. The aerodynamic diameter of air bacteria and fungal spores mainly varies between 0.7-10 µm, which is also within the protection range of KN95 masks. Therefore, the KN95 mask can be used for the respiratory protection of certain particulate matter, such as dust generated during the process of grinding, cleaning and processing minerals, flour and certain other materials. It is also suitable for the liquid or non-oily non-oil produced by spraying. Particulate matter of harmful volatile gas. It can effectively filter and purify inhaled abnormal odors (except toxic gases), and help reduce the exposure level of certain inhalable microbial particles (such as mold, anthracis, tuberculosis, etc.), but it cannot eliminate contact infection, illness or death risks of. The price is $0.70/PC.