STAY COOLER FOR LONGER: The majority of our competitors have only a single 2000mAh battery that translates to only 3 hours of operating time on the highest fan setting. You voiced your complaints and we listened. We specifically engineered two rechargeable batteries for a total supercharged power supply of 4000mAh that lasts 8 hours in the highest speed setting (more than twice the time of our competitors)! POWERFUL YET SILENT: With our newly designed supercharged batteries, our portable personal fans are able to generate up to 3800 RPM in the maximum speed setting while still maintaining a relatively quiet decibel, quiet enough to run in a library. Nothing is more annoying than having an obnoxiously loud fan when youre trying to keep cool in a high ambient temperature environment! ENVIRONMENTALLY FRIENDLY: Our mini fans come with dual rechargeable batteries. This means fewer one-time-use toxic batteries ending up in landfills across the world and instead doing our best to contribute to a more sustainably powered product. MULTIFUNCTIONAL PERSONAL FAN: It can be desktop fan or handheld fan to satisfy your different needs with cool design, you can put the fan upright or diagonally on the table,also great for office. With 3 speed settings, providing strong air flow.