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 2.5L 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 sides Waterproof and breathable outdoor fabric, double stitching cooling channel mesh 2.5L freezable, easy to clean, quick-release bladder 3-speed switch 7.4V 2200mAh battery & charger 2 - 4 hours of cooling from using a frozen bladder, 1 - 3 hours using ice cubes Cooling temperature range 36AdegF-68AdegF (2AdegC-20AdegC), Noise: 48dBA