1Made of premium sponge material, it is breathable and comfortable to wear. 2Washable, easy to use and can be repeatedly used. 3Anti-fog, anti-haze, anti-pollen, dustproof, prevent automobile exhaust pollution. 4Elastic foot, not easy to deform. The double value ensures better breathing and circulation experience. 52 kinds of mouth muffle to choose from, can meet different people's requirements.