Upgraded Version 5-blade USB case fan and brushless motor: Produces a powerful breeze with lower noise (between 20 and 30 dB). Stay cool while making minimal noise so you can work, read or relax without any distractions. 3 Speed Control The fan with 3 airflow speed settings can be adjusted to your requirements. Comfortable first gear with noise below 20dB, conducive to sleep; Second-speed nature designed for work and study; Cool strong third gear, help you enjoy outdoor leisure. Portable and Compact Small (12.5x12.5x5cm) and exquisite, easy to put in a bag inside. Weight (0.18 kg), ideal for outdoor activities and travel, or just to place it on the desk. USB powered with a 1.2m USB cable length, compatible with 5V output USB devices, such as computers, laptops, power banks, portable chargers and other devices with USB output. Cools Your Summer (USB Fan/Mini Fan /Silent USB Fan /USB Fan /usb pc fan) brings you a gentle breeze to keep you cool, it is ideal for office, home, dorm, study, library and leaves little space , which is also ideal for baby's restful sleep.