Bacterial filtration Efficiency(BFE) 98%.
Fluid Resistant.
The mask has white and blue sides, with the white side facing in and the metal side facing up.
Cover the mouth and nose with the mask, and then hang the mask belt on the ear.
Press the metal wire of the upper nasal root of the mask with two index fingers to make it close to the nose skin, and then move the food to both sides gradually, so that the whole mask is close to the face skin.
