Sale Ends Dec 23
Gear up for high-altitude or colder-latitude adventures with the Sea to Summit Alpine -20F down sleeping bag. It offers ample space for gear, and the zip system provides ventilation and versatility.
Fill
850+ fill-power goose down
Weight
3 lbs. 3 oz.
Temperature Rating (F)
-20 degrees (F)
- RDS-certified, 850+ fill-power goose down with a non-PFAS Ultra-Dry Down treatment for maximum thermal performance
- Recycled 20-denier nylon shell with non-PFAS durable water repellent (DWR) is light and durable
- Hood and footbox have a highly water-resistant, breathable fabric for extra moisture protection—ideal for bivys or snow caves
- Highly breathable liner for enhanced comfort
- Roomy, expedition mummy fit provides plenty of space for you, your performance clothing and gear you don't want to freeze
- Free-Flow Zip System features a full-length zipper with a half-length zipper on the 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 sleeping bag
Imported.
Temperature ratings are intended as a guideline to help you compare products, rather than a guarantee of warmth, since many different factors contribute to your comfort while you sleep. Backpacking bags are typically rated for temperature according to an independent testing protocol—currently International Organization for Standardization (ISO) 23537, though some older items followed European Norm (EN) 13537. Testing is based on a person wearing one base layer and a pair of socks, sleeping on an insulated surface with a minimum R-value of 5.38.
Each bag then gets 2 ratings: the Comfort rating is the lowest temperature at which the bag will keep the average "cold sleeper" comfortable, and the Lower Limit rating is the lowest temperature at which the bag will keep the average "warm sleeper" comfortable. Some brands determine their own temperature rating by aligning to the Comfort rating for women’s bags, to the Lower Limit rating for men’s bags, or somewhere in the middle for nongendered bags.
View all Sea to Summit Backpacking Sleeping BagsEach bag then gets 2 ratings: the Comfort rating is the lowest temperature at which the bag will keep the average "cold sleeper" comfortable, and the Lower Limit rating is the lowest temperature at which the bag will keep the average "warm sleeper" comfortable. Some brands determine their own temperature rating by aligning to the Comfort rating for women’s bags, to the Lower Limit rating for men’s bags, or somewhere in the middle for nongendered bags.
| Best Use | Backpacking |
|---|---|
| Tested Lower Limit | -20 degrees (F) - ISO |
| Tested Comfort | -2 degrees (F) - ISO |
| Temperature Rating (F) | -20 degrees (F) |
| Temperature Rating (C) | -29 degrees (C) |
| Weight | 3 lbs. 3 oz. |
| Shell | 100% RCS recycled nylon (hood and footbox non-recycled 10D nylon) |
| Zipper Location | Left/Right |
| Insulation Type | Down |
| Water-Resistant Down | Yes |
| Fill | 850+ fill-power goose down |
| Sleeping Capacity | 1-person |
| Lining | 100% RCS recycled nylon |
| Sleeping Bag Shape | Mummy |
| Stuff Sack Volume | 26 liters |
| Gender | Unisex |
| Sustainability | Down certified to the Responsible Down Standard (RDS) Contains recycled materials |