Features2,000,000 Negative Ions produced with 0.06ppm ozone emmissionRope Design necklace with attachable air purifier, or clip to your collar. Necklace is 45cmSilent operation, fanless designGreat for use outside, planes, trains, shoppingProtects from bacteria, viruses, pollen, PM2.5, dust and pet danderNo changeable filters, just recharge the unit via usb after 28 hours useThe Ible Airvida M1 Wearable Air Purifier is the smallest air purifier around the world. It’s only 20g and easily worn with a titanium necklace or a collar clip for daily clothing. Putting on its charging dock, Airvida M1 can become an elegant desktop air purifier. Airvida M1 constantly creates 2,000,000 negative ions/cm3, 100 times more than natural forest ion concentration, to purify PM2.5, pollen, and smoke around your face. It’s a perfect solution to improve air quality outdoor or in offices, cars, restaurants, public transportation, etc.