Features: 1.The pulse tip technology is used to release a large amount of oxygen anion. The latest double carbon brush double negative ion generator design uses over 6 million negative ions to effectively remove harmful substances such as floating dust, smoke, formaldehyde and PM2.5 in the air. 2.Release a large amount of oxygen anion, kill harmful bacteria, mold and virus, decompose smoke, odor and formaldehyde, benzene and other harmful gases released by car parts (such as sheet, leather). 3.Negative ions promote metabolism, activate cells, refresh and relieve motion sickness. 4.Mini,portable necklace design, stylish and convenient to carry. 5.Easy to operate, one button for on/off.Just press the button for two seconds to enjoy the for fresh air. Specifications: Input voltage: 5V Input power: 0.1W Size: 50x30x39mm Color: Blue/ White Charging time:obout 2-3 hour Length of use:20hours Power Supply:USB battery capacity:350MA Quantity: 1 Set Note: 1.Transition: 1cm=10mm=0.39inch 2.Please allow 0-3cm error due to manual measurement. pls make sure you do not mind before you bid. 3.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you! Package includes: (Without retail package) 1x Air Purifier Necklace 1x Charging Cable 1x Manual