What Our Gearhead(R) Experts Are Saying:"The Mad River 0 is my go-to sleeping bag for cold-weather backpacking and basecamp adventures. The 650-fill ExpeDRY down dries quickly and stays lofty, even in damp conditions, and the wraparound footbox keeps my feet extra warm. I love the dual-zipper design for ventilation when needed, and the recycled shell fabric is a great eco-friendly touch. Whether I'm in the mountains or deep in the backcountry, this bag keeps me warm and comfortable all night."When winter nights set in, the Marmot Mad River 0 Sleeping Bag keeps us warm, dry, and comfortable through the coldest conditions. Designed for backcountry expeditions and basecamp adventures, this mummy-style bag is packed with 650-fill-power down, offering the perfect balance of warmth and lightweight packability. Treated with ExpeDRY technology, the water-resistant down dries quickly and maintains loft, keeping us warm even in damp conditions. A full-length zipper and a secondary right-side zipper provide easy access and ventilation, while the anatomically designed footbox wraps our feet in extra warmth. The draft collar seals in heat, preventing warmth from escaping as we shift during sleep. Made with 100% recycled nylon ripstop shell and lining fabrics, the Mad River 0 is as sustainable as it is reliable. Whether we're tackling a winter backpacking trip or settling in for the night at a high-altitude basecamp, this bag delivers the insulation and comfort we need to rest easy.