built-in battery, light weight, easy to carry, multi-function application, stretchable height, multiple ways of use as one: countertop + floor + storage integrated fan. adjustable airflows are available by easily pressing the power button. It can be powered by a mobile power source, a computer USB port or a power adapter. Built-in 1200mAh battery, fully wireless when used for 6-8 hours, let you enjoy the cool breeze anytime, anywhere. It can be powered by mobile power, computers and other USB ports.