Made of food-grade silicone material, and the elastic silicone perfectly fits the facial skin for a firm seal. The soft silicone will NOT make you feel uncomfortable. Headband can be adjusted. Very lightweight,the surface is smooth and suitable for most people’s faces. It has good sealing and is not sharp. Can be used multiple times (include 10 piece of replacement filler piece), Easy to wear, Environmentally odorless, Smooth breathing, No frost on glasses, avoids the spread of influenza.