Featuring responsibly sourced 850-fill goose down, the Mountain Hardwear Phantom 15 Sleeping Bag provides optimal packability and warmth for the weight. This lightweight bag not only features that premium down, but also features a performance mummy shape for more efficient insulation and less weight and bulk in our pack when we're backpacking or climbing. To keep us extra warm and comfortable, the Phantom also features a four-chamber hood that prevents the down from migrating, a draft collar and down-filled face gasket to prevent heat from escaping, and a contoured foot box to keep our feet in a comfortable, natural position.