Keeping you warm when it's cold outside and cool when the weather warms, the Sea to Summit Ascent AcII sleeping bag does it all with high-quality down insulation and a 3-zipper system for ventilation.
Fill
750-fill-power duck down
Temperature Rating (F)
15 degrees (F)
- Ultra-Dry 750+Loft 90% Down Cluster premium duck down is certified to the Responsible Down Standard (RDS)
- Free-flow zipper system features a full-length YKK® #5 main side zipper, half-length opposite side zipper and a foot zipper to provide ventilation
- Vertical baffles over the chest prevent down from shifting when you roll over in your sleep
- Shaped hood, oversize draft collar and zipper draft tube keep the cold out and the warmth in
- Internal pocket for your phone or other small valuables
- Form a snug double sleeping bag by zipping to any Altitude Journey or Venture sleeping bag (not included)
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 | 15 degrees (F) - EN |
| Tested Comfort | 27 degrees (F) - EN |
| Temperature Rating (F) | 15 degrees (F) |
| Temperature Rating (C) | -10 degrees (C) |
| Shell | 20-denier ripstop nylon |
| Zipper Location | Left |
| Insulation Type | Down |
| Water-Resistant Down | Yes |
| Fill | 750-fill-power duck down |
| Lining | 20-denier ripstop nylon |
| Sleeping Bag Shape | Semirectangular |
| Stuff Sack Size | Unavailable |
| Gender | Unisex |
| Sustainability | Down certified to the Responsible Down Standard (RDS) |