ChiTronic 3.5 Inch Vanes 4400mAh Rechargeable Mini Desktop Fan with High Velocity Battery/USB Powered for Home & Office & Outdoors, Pink Battery type: 4400 mAh Li-ion 18650 3.7V (included) High winds and long life have adequate safeguards. Using the brushless motor industrial grade fans, high winds and long life have adequate safeguards. The integration design, simple appearance, solid structure, it is realize the huge wind capacity fan portable, more confidence in the transport and using. With a USB port make it enable to charge for cellphones via inner high capacity batteries, the fans is very suitble for outdoors activities.