Air Humidification - This usb air purifier is capable of humidifying for a long time to drive away desiccation to make sleep more comfortably ,solution of dry skin help to make skin moist Multi-level Protection - The cool mist humidifier freshner or you can say aroma diffuser vaporizer will auto power off after 6 hours working to prevent dry-fire for safety Wide Compatibility - It is widely suitable air purifier for living room, Hotel, restaurant , hospital, cafe etc.