The Marmot Helium Sleeping Bag packs smaller than a loaf of bread and takes you down to 15F weighing an astonishing 2lb. Versatile and ultralight, this 850-fill down sleeping bag ranks among the lightest on the market in its class. Perfect for spring and fall adventures or even mild winter conditions, the Helium packs away efficiently in smaller packs. Just because its featherlight doesnt mean it skimps on features. A full draft collar seals in precious heat while a mummy shape lets you hunker down when need be. For spring peak bagging and high desert trips, the Helium is your bag of choice.