1. Three-dimensional tailoring, modify the face shape, suitable for most people's face shape, three-dimensional shape, fit the face, reduce air side leakage.
2. Hidden, 5.0 dual core nose strip, it is not easy to break after repeated bending, three-dimensional protection, to prevent the infiltration of pollutants from the gap.
3. Adjustable and shrinkable ear straps to facilitate the comfort of different groups of people