Features 1、[Dual Cooling Modes] This cooling vest features air and water cooling modes, three adjustable cooling gears, providing fast temperature reduction in hot weather. 2、[Water Circulation Cooling] The water flows back through quick connector, bringing a new round of cooling, thereby keeping the temperature of the human body within a comfortable range. 3、[Back Cooling Design] Covering two thirds of the back area, this vest ensures rapid cooling, the waterway layout is carefully calculated to avoid local supercooling. 4、[Adjustable Design] This cool vest allows flexible adjustments in the shoulder and waist areas to accommodate various body types with ease. Additionally, the reflective stripe design enhances visibility for safety and practicality. 5、[Ideal for Various Users] This cooling vest is suitable for athletes, construction workers, and anyone needing cooling, with ergonomic design, providing comfortable experience. Specification Item Type: Cooling Vest Material: Polyester Fiber Battery: Polymer Battery x 1 (Equipped) Battery Capacity: 20000mAh Water Level Requirement: ≥750ml Cooling Method: Air Cooling, Water Cooling Color: Fluorescent Green Size Description: This product has three zips on each side, adjustable in 4 sizes in total. Pulling the farthest zip is the smallest size, not pulling any zip is the largest size, suitable for the majority of people Package List 1 x Cooling Vest 2 x Heatsink 1 x Pot 1 x Refrigeration Water Pump 1 x User Manual 1 x Power Bank 1 x USB Cable