Looking for the absolute warmest bag around? Go for the Men's CWM -40 Sleeping Bag - Long. Built to handle temps as low as -40 degrees F, this bag is a must-have for epic adventures. Premium 800-fill-power down plus waterproof Pertex Shield Fabric keeps you warm and dry in inclement weather, and center and dual side zips make it easy to climb in and out. Features: RDS Certified 800-fill-power goose down provides exceptional warmth, loft, and compactibility Pertex Shield fabric with waterproof, windproof, breathable membrane Internal hood and draft collar cord cinch to prevent heat loss Insulation Material: 800 Fill Power, Goose Down Zipper Location: Center Zip Specifications: Bag Temperature Celcius: -40C Bag Temperature Fahrenheit: -40F Footbox Size: 46.1 in, 117 cm Hip Girth: 58.7 in, 149 cm Includes Compression Stuff Sack: Yes Includes Storage Sack: Yes Includes Stuff Sack: No Insulation Type: Down Shoulder Girth: 65 in, 165 cm Stash Pocket: No Stuff Sack Size: 22.0 x 12.2 in, 56 x 31 cm Style Number: 37050 Product Weight: 5 lbs 6.3 oz,2,447.0 g Marmot Men's CWM -40 Center Zipper Long Sleeping Bag - Clear Blue/Black