The main functions are as follows:

1. The filtration level of the product for non oil particles is level 1, Greater than or equal to 95%;
2. Suction resistance shall not exceed 343.2pa;
3. The water level on the external surface shall not be lower than level 3;
4. According to the specified experimental method, meet the requirements of microbial indicators;
5. The materials used are not inflammable;
6. The mask design has excellent tightness, and the total suitable factor of the mask is no less than 100.