Marmot's lightest 800+ FP down sleeping bag at just 690 grams. The Atom not only impresses with an excellent weight-to-warmth ratio, but also features many other innovative details such as a dual zipper on both sides of the sleeping bag for easy entry, a special YKK Zip-Guard zipper to prevent snagging when opening and closing, and specially shaped down chambers to prevent the down from shifting. The anatomically optimized fit in the foot and head areas makes the sleeping bag particularly comfortable. The Atom is completely PFC-free and is filled exclusively with RDS-certified down. Marmot Down is Marmot's DNA. Since its founding in 1974, Marmot has produced and sold high-quality premium down jackets, vests, and sleeping bags. To this day, Marmot uses only the best certified down for its down outdoor products.