활동

A USB fan is a small and portable device that's handy for personal, close-proximity cooling. As the name suggests, it's powered through a USB connection, such as the one in your computer, a power adapter that you plug into a wall outlet or a portable battery. Some can be self-powered using an internal battery that you recharge — over USB, of course — and, in turn, some of these models can even be used as a portable battery to add some charge to a phone.