Note If you want you buy filter for this product you can buy it in this link ID 1666782 Filter AccessoriesFor Electric Face Mask Features The mask uses filter elemens and high quality polyester soft silica gel of food grade ensure no exotics and no damage and comfortable wear Electric intelligent air purifying technology produce air with high effectivity and actively deliver fresh air HEPA 99 strong filtering effect Right inlet and left outlet make sure air in and out orderly effectively cycling Fit face in 3D and keep good sealing It has large space within mask for air cycling Built in 400mA safety li battery can work for 4 6 hours Charging time only need about 30 minutes Battery life have 3 years at least Protection against gases smells PM2 5 pollen second smoke and pathogens It can be used for Running Travel Dust Air Pollution Motorcycle Sport Specication TypeElectric Air Purifying MasksColorBlackMaterialPolyester soft silica gel of food gradePackage Included 1 X Electric Air Purifying Masks