Combining the best aspects of down and synthetic insulation, the Kelty Dualist 0 Zero Degree ThermaDri Sleeping Bag fills that cold, water resistant, and packable gap in your sleeping bag quiver. The qualities of different types of insulation probably won't surprise you down's light and packable, while synthetic is durable and water resistant but Kelty's innovative design might. Close to your body, warm ThermaDri synthetic insulation retains tons of heat, while water resistant 550 fill DriDown close to the shell lofts quickly to trap more warmth while allowing water vapor to pass through, giving you an ideal blend of warmth, water resistance, breathability, and packability. The Dualist weighs just over four pounds, which is fairly light for a zero degree bag, and it packs down 40% smaller than a traditional synthetic bag, so you'll have more room for layers, snacks, and other essential gear. Kelty didn't skimp on features to save weight, either. The Dualist comes equipped with a warm cinch down Thermal Comfort hood and drawcord draft collar, while the Natural Fit footbox provides a comfortable and warm pocket to keep your toes from turning into icicles. As a final touch, the anti snag tube along the zipper prevents drafts while avoiding zipper complications, so you'll be seriously snug during all your cold weather camping adventures and ski trips.