As close as it comes to a year-round sleeping bag, the Kelty Cosmic 0-Degree Down Sleeping Bag is all about providing comfort in just about any temps, weather, and conditions. The zero-degree rating means this bag will keep us comfortable from early spring to late fall without getting super hot in the middle of summer, and the down fill means that the Cosmic is lightweight and extremely packable. Throw in the materials and we're ready to hit the trail with some -friendly peace of mind.