USB RechargeableWith its built-in high capacity 4200mAh lithium batteries, the portable fan can work for 5.5-13 hours when fully charged. You can charge this mini battery operated fan with any USB device since it is compatible with all USB ports. Five Speeds Adjustable 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 on different occasions. Furthermore, the one-button design allows you to switch between different 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 working. Additionally, the small fan's battery level indicator does also serve as a reminder to charge it before this mini fan runs out of power. Quick Cooling and Removable Fan GuardThe USB fan features five blades to maximise airflow for cooler, softer wind. Moreover, the removable fan guard allows you to easily clean the fan in order to avoid allergies caused by dust accumulation. Low Noise and PortableHigh quality pure copper motor reduces frictional noise and provides strong wind at a lower noise level. With a weight of only 190 grams, the handheld fan can be taken anywhere at any time. You can use it as a hand fan, a neck fan by just hanging it around your neck when you are outside, or as a desk fan when you are working.