Big Agnes Girdle Compression Straps are perfect for Big Agnes Lost Ranger 15 Degree goose down sleeping bag or any stuff sack. Just fit the Girdle over any stuff sack up to 18" long then cinch the compression straps. It's light, easy to use and can compress anything you put in a stuff sack. Try it with your sleeping bag, tent (without poles), clothes, etc. It comes in two sizes: regular and superlight.