The Mountain Equipment Helium is a top quality sleeping bag, EN tested to 0°F. This bag is insulated with 800 down fill, which is ultra-compressible, lightweight and will keep its loft for many years. Helium fabrics are exclusive to Mountain Equipment gear and offer light weight and breathability. All Helium bags have box wall baffles; a lightweight, efficient construction that hold down in place so you don’t experience cold spots. In addition, this line features a 3-dimensional neck collar, for keeping heat in, an anatomical hood and a shark’s toe foot box that allows feet to rest in a more natural position. The down used in the Helium 800 is ethically sourced and blended to ensure quality. These bags have ¾ length zippers to save weight. The Mountain Equipment Helium 800 is everything you want in a 0° sleeping bag. Quality materials, quality construction and thoughtful design; that’s the Mountain Equipment way.