The Slumberjack Sojourn Sleeping Bag offers a lightweight solution for protecting you from the cold with its DriDown technology, which is a proprietary treatment that helps keep the down dryer and loftier longer than untreated down. The bag also offers an "arms out" feature, which, as its name suggests, unzips on the side to allow your arms to move freely while keeping the down attached to your head and chest. This way, grabbing a flashlight, reading or whatever other task you need to perform can be managed without opening your bag and exposing yourself to the elements. Zippers on either side of the bag provide ventilation options that you can adjust based on your ideal sleeping temperature. Small details like that are what make this compressible, 4 lbs., 6 oz. bag a keeper for any cold weather camping. The bag is also temperature rated for -20 degrees Fahrenheit.