The Neutrino 800 Sleeping Bag features 800-fill down for excellent warmth-to-weight ratio. Its hydrophobic treatment maintains insulation in wet conditions. Made with durable Pertex Quantum fabric, it includes a special baffle structure to prevent cold spots. The mummy shape and drawcord hood offer snug warmth, while the internal 3D collar blocks cold air near the zipper. It comes with a dry bag stuff sack to keep the sleeping bag dry during rainy backpacking.