The AlphaCool 7V Circulatory Cooling Vest with a built-in water circulation unit brings the highest quality cooling technology into a compact vest for better wearability and easy operation. It includes a 3L quick-release bladder, a mini pump, a rechargeable battery, and a liquid cooling channel embedded in a mesh liner. The mini pump circulates cold water that will continuously flow throughout the vest, keeping it cool and comfortable in hot conditions. It features a waterproof and breathable outer fabric, 3D material interlay, and a double lines stitching cooling channel layer for maximum comfort.Features:Ergonomically cooling design, front zipper with adjustable sidesWaterproof and breathable outdoor fabric, double stitching cooling channel mesh3L freezable, easy to clean, quick-release bladder7.4V 2200mAh battery2 - 4 hours of cooling from using a frozen bladder, 1 - 3 hours using ice cubesCooling temperature range 36°F-68°F (2°C-20°C),  Noise: 48dBA AlphaCool 7V Circulatory Cooling Vest System