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 as it has been stored at home, there may be slight imperfections. The box, instruction manual, and charging cable are not included. The charging cable can likely be substituted with another one. This includes the water-cooling vest and the battery, a total of two items. The items in the photos are all that are included. Thank you. (^_^)