USB Rechargeable】With built-in 4200mAh high-capacity lithium batteries, the portable fan can work for 5.5 to 13 hours when fully charged. You can charge this battery-powered mini fan with any USB device since it is compatible with all USB ports. Five Adjustable Speeds & One-Button Design】Compared with similar products on the market, the small fan has been innovatively upgraded to five wind speeds to meet your needs in different occasions. In addition, the one-button design allows you to switch between wind speeds by pressing the button and turn it off by pressing the button for three seconds. LED Display】The fan comes with a digital display that shows the current wind speed and battery level when it is working. In addition, the battery level indicator of the small fan also serves as a reminder to recharge it before this mini fan runs out of power. 【Fast Cooling & Removable Fan Guard】The USB fan has five blades that maximize airflow for cooler and softer wind. In addition, the