Designed to deliver restful sleep in the harshest alpine environments, the CWM -40° Sleeping Bag - Long takes the guesswork out of unpredictable weather during your overnight adventures. The waterproof and breathable Pertex® Shield fabric membrane offers protection from Mother Nature's mood swings, while lofty 800-fill-power-down insulation keeps you warm in plunging temps. When it's time to call it a day, give your feet a break in the 11-baffle wrap-around footbox with reinforced lining. The stretch tricot cross-baffle construction controls down shifting and eliminates cold spots. The down-filled draft tube and collar, nautilus 6-baffle hood, and zipper guards limit heat loss in the most extreme conditions.