1. Maximum cooling time of 20h Compared with other hand-held fans on the market, this model is equipped with a larger battery capacity of 4000mAh (twice as large as other models), which can support working time of 5-20h at a time. Battery life depends on different speeds: speed 1 (20 hours); Speed 2(15 hours); Speed 3(5 hours). 2. [Handheld/Desktop Fan] This mini portable fan can be used as a handheld fan outdoors and as a mini desktop fan on a flat table in the office. There is an anti-skid pad at the bottom of the base, which keeps it stable on the table. 3. [USB rechargeable] JISULIFE mini hand fan is USB rechargeable, and it can only be fully charged in 3 hours. It supports USB charging through USB charger, car charger or computer. 4. "Easy to clean & small size" This mini portable fan is equipped with a detachable cover, which can be easily cleaned by rotating it counterclockwise to separate the cover from the fan. In addition, it is small and easy to carry in a bag. Perfect for commuting/traveling/shopping/picnic/office. This will be one of your must-have bags in summer. 5. [Tips] 1. Before using and charging, please make sure to turn on the anti-trigger switch at the bottom of the base. It is designed to be controlled by only one button. Press the button briefly to turn on the fan, and press repeatedly to adjust the wind speed or turn off the fan.