The structure of these fans is unique and fashionable. 3-Mode of wind speed and 1 mode of led light. German brushless dc motor,100% bare cooper to ensure the high winds and long-life. Intelligent control system, reliable performance, which is fully functional and easy operation. Using the international standard 18650 lithium 2200mah capacity batteries, that can be recycled and low cost, more universal. A professional portable fan with integration of design, simple appearance and solid structure. The wind is weak when fan without lithium battery installed but connect to power cable. Depend on availability led indicator and battery type is 18650 lithium rechargeable 2200mah capacity battery output air volume. 1-Speed 873 l/min (work time about 2 hours) 2-speed 459 l/min (work time about 4 hours) 3-speed 242 l/min (work time about 8 hours) output power is 4.5 W (max). Input: 100-240v and ac output is 5v 1a. Dc charging time is about 4-5 hours. Fan charged method- micro usb cable connect to usb port of pc/notebook etc, or by power adapter (not included).