4000 mAh Rechargeable BatteryBuilt-in 4000mAh large capacity battery, can be charged via usb, fully charged in just 4 hours, can provide 4-18 hours of stable work, working hours depend on the wind speed and scenarios you use. Low Noise Bladeless DesignThe bladeless neck fan uses a bladeless design, you do not have to worry about hair being caught by the fan blades, the elderly and children are also very safe to use. Excellent air booster technology, dual-channel air intake design greatly reduces the noise of the fan, below 36db. Three Adjustable Wind SpeedsThis portable neck fan has been improved to operate more easily, press the power button to work, while the power button can also adjust the wind speed. A total of three wind speeds - high, medium and low - are available for you to choose from, making it ideal for personal cooling, indoor cooking, reading, watching sports, working, outdoor activities such as camping, traveling, hiking, fishing, climbing and cycling, etc. Optimized Ergonomic DesignThe adjustable twist airline memory neck strap can be bent up to 160 to accommodate all neck sizes, which ensures a perfectly snug, more comfortable fit. After Sales ServiceWe are committed to providing all customers with a quality shopping experience, if you have any questions about our neck fans, please feel free to contact us, we are willing to serve you anytime.