Refuel on your next below-freezing backpacking adventure in the ultralight, eco-friendly gas bags, featuring a new sustainable ExpeDry water-repellent technology that increases performance and reduces the drying time of your down bag. With an optimal ISO-tested comfort well below freezing, the Helium 15° Sleeping Bag will keep you toasty from head to toe in a super-packable 800-fill-power down bag designed to easily stuff into any overnight pack. A thru-hiking favorite, the new gas bags provide lightweight warmth that's light on the Earth—perfect when you're looking to maximize miles or speed in the mountains and minimize weight and space in your pack. If going tent-less is in the plan, you can count on the quick-drying ExpeDry to perform as a bivvy sack on cold, wet, or snowy ground or ledges.