Multi-function: Press the on/off key for three seconds to and shut down, and short press to switch the power. Enjoy at any time, improve depression, insomnia, mood, and sleep quality. No noise, low power consumption, 5 decibel ultra-quiet operation to sleep quality About this product Protective effect: The ions of the wearable air purifier form an protective cover, which can resist PM2.5, pollen, dust, second-hand smoke and other pollutants, creating a private space. Negative ion generator: a device that generates negative air ions, removes dust and purifies the air. The necklace releases negative ions to drive harmful air pollutants away from the breathing area Stylish and convenient]: Small size and light weight. Can be hung on the neck, handbag, car trouser hook, stroller, camping or bedside table. The stylish design blends in with your clothing. Compact design for easy travel