Plugs into your smartphone. Inner plug is a 2-in-1 plug (Micro USB + Lightning) and the outer plug is a Type C connector. Immediately activates to cool you off. Powerful and soft blades move with quiet operation. Works with most newer Apple, Samsung and Android smartphone devices. Includes a diode which; prevents voltage from being kicked back from the fan, thereby protecting the device. This is a very important safety feature some lower cost fans do not have. Some phone cases prevent the fan from plugging in completely, before returning the fan, remove the case and try it again. From research, cell phone retailers have found that most users frequently overcharge their phones. This reduces the life of the battery and/or the capacity. The fan must have a fully functional battery to operate properly.