Power supply: USBSpecification: Length 173*Width 160*Thickness 100MMNoise: 45-50dB(including)Rated voltage: 5Rated power: 4Wind speed: 3 speedsOperation mode: touch typeWhether to support charging: supportPackaging volume: length 165 * width 87 * height 17.6MMBuilt-in battery: Removable batteryBuilt-in battery capacity: 1200mA-2000mAMotor Type: Brushless MotorNumber of fan blades: 3Fan Category: USB FanDesktop Fan: 5 inch large wind power, touch button, three wind speedsSize: 5 inchDuration: 3-6h(including)Additional features: touch buttonIncludes: 1X Fan1. 1-3 cm error exists due to manual measurement, which is normal. 2. Due to different screen or computer settings, the color may be slightly different from the picture. If there is any problem with the product, please leave me a message in time. I will surely solve the problem quickly and effectively. Please do not complain before sending us a message as it may take more time to solve the problem. Ships from China in 2-4 days after order, delivered in 15-25 working days Q: Do you provide invoice? A: We provide digital invoice, if you need it, you can send us a message after placing the order. However, this invoice can not be used as a tax invoice, it has no company stamp.