N95, KN95, FFP2, KF94 refer to the mask level, just different standards for the use of epidemic prevention masks in different countries, but with the same blocking epidemic prevention performance. The N series of masks is the American standard, KN series is the Chinese standard, FFP series is the European standard, and KF series is the Korean standard. And the number after refers to the protection ability, the bigger the number, the higher the protection level. The higher the number, the higher the protection level. 95 refers to the efficiency of filtration of such particulate matter up to 95%. Therefore, the filtration capacity of these masks is FFP3>FFP2=N95=KN95=KF94>KN90.