USB Rechargeable: With 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 as it is compatible with all USB ports. Five adjustable speeds and one button design:Compared to similar products on the market , the small fan has been innovatively upgraded to five wind speeds to meet your needs on different occasions. In addition, 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 display: The fan comes with with a digital display that shows the current wind speed and battery level when it is working. Moreover, the battery level indicator of the small fan also serves as a reminder to charge it before this mini fan runs out. Rapid cooling and removable fan guard: The USB fan has five blades to maximize airflow for cooler, smoother wind. In addition, the removable fan guard allows you to easily clean the fan to avoid allergies caused by dust accumulation. Low noise and portable: The high-quality pure copper motor reduces frictional noise and provides strong wind at a lower noise level. With a weight of only 190 grams, the portable fan can be taken anywhere and anytime. You can use it as a hand fan, a neck fan by simply hanging it around your neck when you are outdoors, or as a desk fan when you are working.