Created for specifically for alpine activities like mountain climbing and backpacking, the 650-fill down inside the Sub Zero Vest is superb insulation for a wide range of outdoor activities, including camping, kayaking, spring skiing and more. The one-hand hem drawcords along the back and hem let you pick a fit that matches the conditions. You'll also find a waterproof stuff sack included for convenient storage inside your backpack, kayak or adventure travel bag.