Used for a few hours, about twice. The "Ice Drip Control" system efficiently creates cold water by slowly allowing water to flow down the sides of a frozen PET bottle. A quiet pump circulates the cold water throughout the tubing. ○ Ice Man Vest x 1 ○ Lithium-ion battery 3350mAh ※ PET bottle not included. Please purchase a commercially available bottle and freeze it for use. ※ This product does not include a charging adapter. Operation has been confirmed.