KF94 is a mask that can prevent the new coronavirus to some extent, but it does not completely prevent the new coronavirus infection. The new coronavirus is transmitted into the respiratory tract through droplets, and the production standard of KF94 mask is that the particle filtration index is 94% or more for particles of 0.4 microns on average, which means that the filtration rate is greater than 94% for particles of 0.4 microns in diameter, the face leakage rate is 11%, and the face suction resistance is 70 Pa, which can be applied to the face to stop airborne droplets. Therefore, KF94 masks can prevent respiratory infectious diseases, including the new coronavirus, to some extent, but not completely, and require users to observe the correct method of wearing masks and other means of protection. The KF94 mask can be worn throughout the entire process of entering a crowded area. It is recommended that the mask not be used for more than 8 hours and that it be replaced promptly if it is found to be broken in the process of wearing the KF94 mask. In addition to wearing a mask, it is still recommended to minimize outdoor activities, to do a good job of personal protection, to strengthen exercise, and to improve personal body resistance.