Product details:

Looking for the absolute warmest bag around Go for the Men's CWM -40° Sleeping Bag. 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.Regular size: suits max. 183 cm users, shoulder girth 160 cm, hip girth 144 cm, foot box girth 112 cm.
Insulation down: fillpower 800, amount 1419 grams, RDS certified.
The down is Down Defender treated to repel moisture.
The surface fabric is Pertex Shield ripstop nylon, made from recycled fiber.
The lining fabric is recycled nylon, with reinforcements at the foot end.