Unique structure fashionable Small and exquisite. easy to carry Ball fan. wind strong and durable Digital control. simple operation Machine welding. stable and reliable 18650 Lithium-ion battery. lasting power Battery is removable. easy to replace USB connector. easy to charger High efficiency and low loss. energy saving and environmental protection Specification: 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: 4 W (Max) Battery: 18650 Lithium-ion battery Charger: Input: 100-240V AC Output: 5V 1A DC Charging time: about 5 hours Dimension: 4.33"x 3.54"x 1.38" (11 x 9 x 3.5 cm)