1、Stay Cool and Comfortable: Cooling vest features TPU composite waterways, adjustable three level cooling, and dual switches for both air and water cooling. Designed ergonomically for a comfortable and intelligent cooling experience. 2、Rapid Cooling Technology: Utilizes a quick connect flowback system to initiate a new round of cooling, maintaining the body temperature within a comfortable range for extended periods. 3、Targeted Back Cooling: Extensive testing reveals that cooling the back area is more comfortable, covering 2/3 of the body's back region for fast and efficient cooling. Accuracy designed waterways prevent localized overcooling. 4、Innovative Design for All: Constructed with robust composite materials and innovative craftsmanship, featuring adjustable shoulder and waist straps for a personalized fit. The vest style design is adaptable to various body shapes, with reflective strips for safety and aesthetics. 5、Versatile Cooling Solution: This cooling vest is ideal for athletes, construction workers, and individuals. Suitable for anyone in need of heat relief. Item Type: Cool Vest Material: Polyester Fiber Battery: Polymer Battery x 1 Battery Capacity: 20000mAh (Shipped with Matching Battery) Rated Voltage: DC12V Water Requirement: ≥750ml Cooling: Air Cooling and Water Cooling Size: 4 different sizes adjustable with 3 zippers on each side, the smallest size is when all zippers are pulled to the far end, and the largest size is when no zipper is pulled, suitable for the vast majority of people 1 x Cooling Vest 2 x Heat Sink 1 x Ice Crystal Bottle 1 x Cooling Water Pump 1 x User Manual 1 x Power Bank 1 x USB Cable