the Portable USB Fan has unique design and upgraded funtions. In addition to the small size and light weight as regular portable fans, there is a hidden hook in it, which is suitable for outdoor equipments such as backpack, tent and bicycle. And its 180° rotation setting makes it act like either a desk fan, or a hanging fan, or a handhold one. 3 wind speeds (2000RPM - 2600RPM - 3200RPM) can fit different requirements, and either mode would cause little working noise (35db). In dark environment, the fan also helps due to its inner LED light. The 10000 mAh battery can support for up to 50-hour use, not to mention the fan is rechargeable with any USB-friendly appliance.