SIZE:17.5cm 9.5cm - 3Ply. PERFORMANCE: Soft Touch, Odorless, Tasteless, Flat, Good tightness. To keep out the spray, dust transmission or invasion of the human body. East to wear. STRUCTURE AND COMPOSITION: Non-woven fabric with inner and outer layers. The middle layer is the melt-blown adsorption barrier filter layer and elastic ear band. Scope of application: For medical institutions, schools, general protection for public transportation and family use. It is used to protect against viruses, froth, dust enters the body or spreads. NOTES: 1. Use as soon as possible after opening the package. 2. This product is disposable and should NOT be used repeatedly. Replace or discontinue use when suction resistance is increased. Recommended to use not to exceed 4 hours. 3. Please check whether the package is in good condition before use. Do not use the damaged package. 4. Use with caution if allergic to non-woven fabric. STORAGE: Recommended for clean storage, dry ventilation, in a non-corrosive gas environment. Stay away from sparks or flammable materials. Validity: 2 years.