The Tension Mummy 500 is a mildly heavy weight high insulation down bag constructed in the comfortable "mummy" shape that provide a roomy and comfortable nights sleep. The bag is made for any trip to the outdoors where the temperature will drop to freezing cold, and the lightweight outer casing fabric keeps the weight down while still providing a durable sleeping bag. The full length zipper is down covered to keep the hot air inside the bag where you can enjoy it, and the adjustable contour hood gives the bag a good feel if you sleep with your head inside it.
Energetically, geese and ducks are the most efficient combined heat and power plants of all time. Thousands and thousands of super-soft filaments, consisting of the horn substance keratin, grow radially from a tiny core. Each of these filaments is provided with innumerable fibre ramifications. If many down come together, they stick together with their hooks and form many small heat-storing air chambers. A natural system that is lighter, more flexible and better insulated than anything man has ever invented. Yeti goose down achieves the highest possible bulking power of up to 900 cubic inches (cubic inches). Yeti exclusively uses European down, mainly from Germany and Poland. Every single down complies with the EDFA Traceability Standard.