ALPS Mountaineering Silverthorne 5 Degree Sleeping Bag. The ALPS 5 degree Silverthorne Sleeping Bag uses a 2-layer construction featuring 70D hollow fiber polyester insulation to help eliminate cold spots and keep you warm. There is also a zipper baffle to help seal in your body heat. It is composed of a 100% cotton flannel liner that is comfortable and soft to the touch plus a rugged cotton canvas outer. When it’s time to store or transport the bag, it conveniently rolls up with the roll-up straps so it’s easy to carry and doesn’t take up too much room. Two Silverthorne bags can be mated together to form a double bag. Size: 38″ X 79″ Total Weight: 9 lbs. Stuff sack size: 14″ x 24″.