Gear up for your next high altitude or colder latitude adventure with the Alpine Down Sleeping Bag. The expedition mummy fit provides ample space for winter gear, while the modified Free-Flow Zip system provides ventilation and versatility. Complex construction throughout and 850 fillpower, RDS-certified PFC-free Ultra-Dry Goose Down delivers maximum warmth retention. Features RDS-certified, 850 fillpower goose down with a non-PFC Ultra-Dry Down treatment for maximum thermal performance Recycled 20D nylon shell material with PFC-free DWR is light and durable Roomy expedition mummy fit provides plenty of space for you, performance clothing and gear you don't want to freeze Highly breathable liner for enhanced comfort Free-Flow Zip System: Full-length zipper with half-length zipper on opposite side for excellent temperature regulation Technical hood and footbox, efficient mummy shape and generous draft tubes on the zippers maximize warmth retention Sea to Summit Guarantee is offered for the Lifetime of this product