USB RechargeableWith built-in 4200mAh high capacity lithium batteries, the portable fan can work for 5.5-13 hours when fully charged. You can charge this battery operated mini fan with any USB device since it is compatible with all USB ports. Five Adjustable Speeds and One-Button DesignCompared to 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 DisplayThe fan comes with a digital display that shows the current wind speed and battery level when it is running. 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 CoverThe USB fan features five blades that maximize airflow for cooler and smoother wind. Plus, the removable fan guard lets you clean it easily to avoid allergies due to dust accumulation. Low Noise and PortableHigh quality pure copper motor reduces frictional noise and provides powerful wind at lower sound level. With a weight of only 190 grams, the hand fan can be taken anywhere and at any time. You can use it as a hand fan, a neck fan by simply hanging it around your neck when outdoors, or as a desk fan when working.