[Working Hours Duration]: This fan can work between 10 to 40 hours depending on its speed. Three times longer battery life than the average ones. [Strong Airflow and Foldable Design] - speed 1 with 2400 RPM, speed 2 with 3100 RPM, speed 3 with 3600 RPM, has strong airflow to keep you cool. The foldable design makes it easy to be carried and stored. [DC Brushless Motor, Adjustable Tilt] - Using energy saving DC motor, up to 20000 hours working duration. The fan can be adjusted from 0°to 180° to satisfy your needs. [Multiple Power Supplies]The ease of use is what OPOLAR always brings to you. This fan comes with several power supply options so you can use it on batteries or via USB by connecting to a computer, etc. You can even power the fan with a wall adapter. [Multi-functional and User-friendly] With a humanized handgrip design, it is Foldable, it can be used as a desk fan or handheld fan. Has a hanger and a metal clip that can be applied to office card. Note! OPOLAR offers a one-year warranty.