This air more energizing creats as a lot as 120millon / cm³ unfavorable lons Helps to get rid of PM2 air pollutants, smoke, odors, dust,etc. Silent operation and simple to use No extra clear out obligatory If you would like have a more in-depth immune components within the flu season, give up allergy symptoms from bothering you, boost your metabolism, this transportable device is a reasonable option. Product Specification: Name: Air Purifier Necklace Working voltage: DC5V Power: Less than 1w Negative ion concentration: 80-120millon / cm³ Battery capacity: 250mAh Charging time:1h Working time:24-30h Weight: 30g Colour:black Material:ABS Size:4 x 7 Package Contents: 1 * purifier 1 * usb cable 1 * lanyard Only the above kit content, different item should not included. Note: Light shooting and assorted reveals could cause the color of the thing within the picture a bit diversified from the real thing. The size allowed error is +/- 1-3cm.