The Kelty Cosmic sleeping bag is a three season bag that includes a stuff sack. As a mummy sleeping bag, it has a full draft collar and draft tube to keep you warm on the coldest nights. While it is not recommended for year-round use, these sleeping bags have a temperature rating to 20 degrees Fareneheit. All this together makes the Kelty Cosmic one of the best sleeping bags.\r\n\r\nWhy We Like It - Kelty Cosmic 20 Review\r\nThe Kelty Comic 20 is a well constructed sleeping bag that is ideal for cool weather sleeping. Rated to 20 degrees, this three-season sleeping back has compression sack included and can be purchased with free shipping. It is constructed from high quality materials and has a durable nylon taffetta shell fabric.\r\n\r\n\r\nPerformance\r\nThe Kelty Cosmic has a two-way locking anti-snap zipper that allows you to dual zip the lining closed, or keep it open on warm nights. While the 600 fill dridown helps to keep you comfortable, a sleeping pad can add an additional layer of cushion as you sleep. There is plenty of room inside the sleeping bag for a pad, regardless of style you choose. A small electronics pocket is a nice feature for those who want an alarm to wake up and hit the trails early, or map out your route while you wind down before falling asleep for the night. You would have never seen a feature like this years ago, but it is nearly a necessity in this day and age.\r\nDesign\r\nThis nylon taffetta shell, water resistant sleeping bag is constructed from highly durable materials. It has a 50D polyester taffeta liner and a 600 fill power dridown insulated core. Its fill weight ranges from 18.2 to 33.3 ounces depending on the style purchased. All together you get a 20 degree bag that will keep you comfortable three seasons a year. In addition to the dridown being an insulator, it is also environmentally friendly. While each down plume is hydrophobically treated with a molecular level polymer, to maintain its fast-drying features, the treatment is PFC free, making them safer for the planet.\r\nValue\r\nAs a middle of the road sleeping bag, price-wise, the Cosmic 20 is rated as a moderate value product. Compared to the Teton Sports Leef 0 Sleeping Bag, the Kelty is twice the price and cannot be used year-round. However, the unzippable outer layer and electronics pocket are nice features not found in either the Teton or Winner Outfitters Mummy sleeping bags. When compared to the Western Mountaineering Summerlite Mummy 32F Sleeping Bag, which is lighter, the price and additional features are a big win for the Cosmic 20.\r\nKelty Cosmic 20 Review Wrap Up\r\nWhile priced a little on the high side, the electronics pocket and dual zip outer layer are nice features. Even though the bag is not ideal for year-round use, the Kelty Cosmic 20 is a decent mummy sleeping bag when compared to competitor\u2019s products.