USB Charging: Equipped with a Type-C charging interface, a built-in 3000mAh lithium battery with large capacity, the USB fan can work for 4-10 hours after full charge. Compatible with 5V output adapters, laptops, computers, chargers and other USB-equipped devices. The USB output of the hand fan can also be used as an emergency power supply in an emergency. 【4 Adjustable Speeds】The mini fan supports simple one-click adjustment of 4 speeds: 1-3 speeds with growth, 4 speeds of circulating wind (the circulating wind automatically switches between the 4 wind speeds above and experience the fun of intelligent speed change) to meet your different needs. (Hold for 3 seconds to turn off). LED Battery Indicator: The foldable fan is equipped with a clear LED digital display, which can show the exact battery level and current wind speed during work. It serves as a low battery reminder to remind you to charge this portable fan in time. 180° FOLDABLE MULTI-PURPOSE DESIGN: The handle of this