Efficient Filtration System: The air filter using pulsed tip technology to release a large amount of negative oxygen ions(PM2.5), efficiently remove dust, smoke, haze. Air Purifier with No Chemicals: This portable wearable air purifier has no chemicals and can release 10,000,000 negative ions. And there is no need to replace expensive and cumbersome filters. Wide Range of Applications: Personal air filter can use on your neck, hand, car, backpack, Baby Stroller or Compact enough to fit on your desk. Effective your area (bedroom/ office). Rechargeable Air Cleaner: USB charging(Included USB cable), charge 2 hours can be used for about 30 hours.