Sport Cooling Vest Evaporative Cooling by Technique using HyperKewl is a simple and effective technology that works by combining water with the HyperKewl Fabric to create garments that gradually release water through evaporation to keep you cool, but comfortable. Kids get hot too and will enjoy wearing there sport cooling vest. The vest has a V-neck design with a zipper front. Quilted Nylon outer shell with Hyperkewl polymer embedded fabric inner, water repellent Nylon liner and a Black cotton Poly elastic trim all around. Your choice of either Blue or Silver.