KN95 Protective Breathable Outdoor Face Mask with Nose ClipKN95 mask can isolate smaller particles, and fit tighter to the face, it is not easy to leak air from the periphery, and the filtration efficiency of particulate matter can reach 95% under standard conditions. Features: 4 Layers Filter function: The first layer: spunbond cloth, filter the dust of micron. The second layer: to filter industrial pollutants, automobile exhaust, second hand smoke pollen allergies. The third layer: activated carbon cloth,