The Silver Creek uses a 2-layer construction to help eliminate cold spots and keep you warm. It also has a zipper and chest baffle to keep your body heat inside the bag. It's composed of a polyester outer and liner and comes with a standard stuff sack. When the temps are expected to dip down in the 20's be sure to bring along the Silver Creek for a positive experience. Features: - Bag Shape: Mummy - Temperature Rating: 20? - Two layer construction - Fabric Color: Green/Black - Outer and Liner Material: 190T polyester - #5 separating zippers - Zipper and chest baffles - Standard stuff sack included Specifications: - Color: Green/Black - Total Weight: 4 pounds 7 oz. - Fill Weight: 40 oz. - Dimensions: 33" x 84" - Temperature Rating: 20?