4000mAh battery capacity. Compared with other portable fans on the market, this model is equipped with a larger battery capacity of 4000mAh (twice as large as others), which supports 5 to 20 working hours with a full charge. Battery life depends on different speeds: Speed 1 (20 hours); Speed 2 (15 hours); Speed 3 (5 hours). Portable/Desktop Fan. This portable mini fan can be used as a handheld fan outdoors and as a mini desk fan on a flat surface in the office. There is a non-slip mat at the bottom of the base to keep it stable when placed on the table. USB Rechargeable. This mini hand fan is USB rechargeable and takes only 3 hours to fully charge. It supports USB charging via USB charger, car charger, or computer. Easy cleaning and compact size. Equipped with a removable cover, this portable mini fan is easy to clean. Simply rotate anti-clockwise to separate the cover from the fan. Additionally, its compact size allows for easy carrying in your bag. Perfect for commuting, travel, shopping, picnics, or office use. It makes for a summer essential to carry in your bag. Warm Tips: 1. Before use and charging, ensure the anti-tripping switch at the bottom of the base is turned on. 2. It features one-button control. Short press the button to turn on the fan, press repeatedly to adjust the wind speed, or turn it off.