Water tank circulation type cool vest, equipped with a 3350mAh battery, allowing for approximately 2 hours of cooling. - Model Name: DIRECT COOL DC-B01S - Battery Capacity: 3350mAh - Cooling Method: Water tank circulation - Cooling Water Tank Capacity: 150ml - Cooling Time: Approximately 2 hours - How to Use: Uses a plastic bottle Thank you for viewing. This is a new, unused item, but it has been stored at home, so there may be slight imperfections. The box, instruction manual, and charging cable are not included. I think a charging cable can be substituted with another one. This includes the water cooling vest and the battery, for a total of two items. Everything in the photos is included. Thank you. (^_^)