DESC: Just because you sweat all day doesnat automatically mean youall be warm at night. The Big Agnes Yampa 45 Degree Down Sleeping Bag comes with 650-fill down insulation to trap in your warmth once the sun goes down and when the front blows through the mountains. Before you turn in, slide your 20-inch-wide sleeping pad (sold separately) inside the Yampaas bottom pad sleeve, and rest easy as you dream about happy trails.