Filter mask helps decrease the transmission of flu & coronavirus/COVID-19. The product is Non-woven fabric such as ultrasonic heating, spot welding and banding with processes, Cellulose and paper / plastic-coated carbon steel, Disposable. Air permeability, Hypoallergenic. They are able to block dust and it will not cause tension or anaphylactic reaction for long-term wearing. Smooth cloth is adopted to reduce the falloff of fabrics, which is wash-free, maintenance-free, convenient, practical, safer and more healthful.