USB fans are more advanced types of fans which can be used anywhere to enhance air circulation and provide a cool refreshing breeze. They are normally powered by different devices that have USB ports such as computers, laptops, power banks among others. Their compact and lightweight designs ensure easier portability. Moreover, most of them can also be adjusted to different angles, inclinations and heights for convenient use. In fact, some of the best USB fans come with rechargeable batteries, which enable them to be used even when the USB device is switched off.