This air purifier is characterized by its ability to generate negative ions. Anions are used to improve the body's metabolism and homeostasis. High Efficiency: Our personal portable air purifiers can release as many as 15 million negative ions, reducing energy consumption and improving energy efficiency. Mini Portable: You can wear it around your neck, and it's portable, usable anywhere without noise. The product does not need to add any water or liquid, it starts purifying the air. Great Gift: Stylish design makes your surroundings more colorful and fun. Perfect for family and friends. Input Voltage: 3.7V (Battery), 5V (USB power) Power Consumption: Less than or equal to 0.5W Charging Time: Approximately 45 minutes Battery Life: Approximately 8-10 hours Ambient Temperature (operation): -5 Celsius - 45 Celsius Color: White Material: ABS Size: 45 x 13mm Package Contents: 2 x Air Purifier 2 x USB Cable 2 x Lanyard Only the above package content, other products are not included. Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3 cm.