When winter camping in the Rockies, rely on the Mammut Alpine UL 10 Degree Synthetic Winter Sleeping Bag to keep you warm. Mammut's MTI Endurance synthetic insulation has an excellent warmth to weight ratio and will still insulate if the the bag happens to get wet throughout the night. The bag's ProlightTX outer fabric is not only lightweight, but it blocks wind and is water resistant, making the bag well suited to tackle wet winter environments. The hood is designed to provide a full field of vision when you're hunkered down, without compromising insulating capabilities. In addition to the hood, the bag is fitted with an insulated draft collar to trap warm air.