?Customer Service? Provide free online customer service. We promise to answer within 24 hours . If you have any questions, please feel free to contact us, we are willing to answer your questions. ?High Compatibility USB-powered ?The SmartDevil USB fan is powered by USB and compatible with PC/laptop, power bank, AC adapter, car charger and other USB-enabled power supply.USB fan is energy-saving and environmentally friendly. (Note:This fan does not carry a battery). ?Three-speed Adjustable? Low/medium/high speed level. Adjust appropriate fan speed by pressing the power button repeatedly. Third gear which can be variable speed design provides you more choices in different temperature environment. ?Ultra-Quiet?The small usb desk fan uses a silent structure which is engineered to be ultra-quiet while delivering high airflow. Better accompany your work or sleep without disturbing you. ?Exquisite Design?ONLY 6 oz! Compact lightweight design for maximum convenience. Small and lightweight personal fan provides cooling air circulation in any desired directions with 360 degree tilt rotation.Perfect for use in home,car, office, desktop, camping, or travel.