The Drift 0 sleeping bag is designed for adventurers that like to head out even when it's cold. Our 32oz of 850+ fill power DownTek® down will keep you toasty warm down to zero degrees. The Halo Neck Collar traps all your body heat inside the bag while not allowing any cold air in that might disturb your night's sleep. All Brooks-Range sleeping bags are design for one goal: To keep you comfortable while sleeping. Our bags have a streamed line design, we only add features that help increase the bag warmth.