Compared with other products on the market, this mini usb fan is unique in that it works very quietly,up to 34 decibels in 2nd , similar to the 1P conditioner used in the room Upgraded version,double blades rotate in opposite directions driven by different motors to blow cooling & .The output of the product is adjustable. There are a of three gears, 0 gears are closed, and 1-2 gears are corresponding to different wind .The rear cover of the product is detachable,very easy to clean.The double Blade mini fan can be adjusted up and down by 30 degrees to meet your needs. The small desk fan uses a high-quality motor,which rated life of 1400 hours.Interface: USB 2.0/3.0Electric supply: DC 5V 1.2WRated life: 1400 hoursLength of USB cable: 44 inchProduct size: 15.23 x 11.4 x 8.1 cmWeight: 458gcolour: blackMaterial: ABSPackage Contents:2 x USB mini fan2 x packageOnly the above package content, other products are not included.Note: Light reflection 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 +/- 1-3cm.