Product Overview: AT Hybrid’s insulated, windproof body panels and side panels with 4-stretch are a winning combination. The 37.5® insulation keeps you comfortable by helping to control your core temperature while the stretch panels enhance fit and freedom of movement. The AT Hybrid Vest is an ultra-lightweight technical piece that is flattering and comfortable. Features: Stretch side panels for fit and freedom of movement 37.5 technology is chemical free, permanent, and never washes out or gets tired. Stand-up, zip-through collar with chin-guard Zippered hand warmer pockets