LOHOME(TM) USB Powered No Leaf Bladeless Mini Air Fan Portable Cooling Fan With Stand (Pink) The principle is simple and unique, creating two efficacy of normal blowing or cool breeze for choice (built-in sponge for absorbing cool water and freeze to generate cool breeze.). Keep the air humidity and let you say goodbye to summer heat waves. Powered by the included USB cable or 4 * AAA batteries (not included). Bladeless safe design, free from injury by blades especially to children. Low noise will not disturb you when working . Come with a built-in stand on its back, to well support the mini fan on smooth surface such as a desk or an office table for use.