Just attach, turn on, and let the cool airflow! This portable personal cooling fan features a sleek, innovative design that allows versatile hands-free use anytime, anywhere! The 5V battery fan's clip-on design allows clipping or hanging it around the waistband of your pant. Cover the bottom of your shirt to cover the clip fan and plug the cord on its side into the power bank (battery). This portable clip fan is powered by a 3000mAh battery (included) but you can use any off-the-shelf phone charging power banks for additional power or extended run time. You can select from the 3-speed settings available on the controller of this handsfree cooling fan to adjust the breeze.