SkyGenius Portable Handheld Fan, 4000mAh Rechargeable Battery/USB Operated Mini Cooling Fan for Home Office Outdoors Travel Black

• 【POWERFUL YET SILENT】: With our newly advanced technology, our portable fans are able to generate up to 3200 RPM in the maximum speed setting while still maintaining a relatively quiet decibel, quiet enough to run in a library. 【LONG TIME OPERATION AND USB CONNECTION】:4000mAh large capacity batteries provide 5-20 working hours duration (depend on different speeds). Batteries are rechargeable and irreplaceable(for safety). USB charging by a computer, laptop, power bank,USB Charger, cellphone adapter, car charger etc. This hand fan will work on 110 or 220 volts which can be carried to all over the world. 【PORTABLE & COMPACT SIZE】: It is of small in size (4.1-inch wide and 7.8-inch long) and can easily fit in your pocket, backpack, or beach bag. You can carry it with you easily when you go out for a picnic, shopping, traveling, camping, etc. 【FAST CHARGE AND ONE-KEY OPERATION】: Fans gets charged in 3 hours only while other similar fans need 6 hours. The battery of this fan has been designed for the current input of 2A (others 1 A), which makes it get charged faster. Besides, It is easy to use this mini battery fan with only one button. Short press the button to turn on the fan, and press repeatedly to adjust the wind speed or turn off the fan. 【DESKTOP DESIGN】:The cover can be rotated as a base, so you can also use it as a desktop fan.