This bag is constructed with Sierra Designs' UltraLight Stretch construction so the bag stretches in response to pressure increasing the girth of the bag when needed. A waterproof/breathable membrane both inside and out will keep this down bag dry and at close to 1 1/2 lbs. This is a summer dream bag. We have used this on short bivies on technical climbs with great luck. Rated to 30 F.

Sierra Designs Moon Light

Sleeping Bags **Expedition Bags** Bison - Down Dark Star - Synthetic Puma - Down Tundra - Synthetic **4 Season Bags** Antelope - Down Snowshoe - Synthetic Night Light - Synthetic Night Delight - Synthetic Superlight - Down **3 Season Bags** Cats Meow - Synthetic Goliath - Synthetic Dream Machine - Synthetic Dreamweaver - Synthetic Moonlight - Down Sweat Dreams - Synthetic