This is a workhorse of a sleeping bag. Lightweight for backpacking ease, but comfortable and warm enough for all-occasion three season use. The Kelty Cosmic 20 Synthetic Sleeping Bag is the quick-drying synthetic version of Kelty's flagship out-of-this-world backpacking bag. Shoot for the stars, and even if you miss, you'll end up napping in your Cosmic sleeping bag because that's a super long hike to get to the stars.