Sea to Summit
AP III -4° Sleeping Bag
Product Number: 25322
The Sea to Summit AP III -4 degree sleeping bag is part of the Alpine Series, the ideal refuge for high-altitude expeditions and the most extreme cold conditions. This down sleeping bag is EN-rated to a lower-limit temperature of -4 degrees F and a comfort temperature of 10 degrees F.
The Alpine Series of down sleeping bags are intended for alpine use, providing a warm cocoon for high-altitude and arctic conditions. The patent-pending 3D NanoShell™ technology repels external moisture and keeps condensation away from the down insulation. Sea to Summit uses the highest-quality European goose down available, rated at 850+ loft and backed up by a certification document included with each sleeping bag. Innovations like the 3D Sidewall and Reverse Differential Cut keep the insulation in place, and close to your body, for maximum thermal efficiency. Temperature ratings are the result of honest, third-party EN testing performed on each sleeping bag.
Designed with a contoured mummy fit and anatomical foot box, the AP III traps warmth effectively without inducing claustrophobia. Side block baffles maintain a 60:40 fill ratio, with more insulation atop the bag where you need it most. An oversized neck collar, hood seal and zipper draft tube minimize heat loss. The soft-touch lining fabric is highly breathable for comfort, and a stiff anti-snag material lines the zipper. An easily-accessible security pocket inside the bag is ideal for stowing electronics in extreme cold.
The Alpine Series is Sea to Summit’s choice for Karakorom expeditions, alpine routes in the Andes, Himalayan high-altitude climbing and winters in New Zealand. These down sleeping bags are so revolutionary we can’t fit all of the information here, so check out this series of articles on our blog!
* This product does not qualify for shipping to all countries.
- Contoured mummy
- 3D NanoShell™
- Differential cut shell with 3D side walls
- Offset baffles
- 60/40 fill ratio
- Side block baffle
- Anatomically tapered foot box
- Zip draft tube with anti-snag
- Neck draft tube with dual elastic adjustment
- Cushioned internal hood drawcord with dual adjustment
- 2 way YKK #5 side zip
- Medium sized internal zip pocket
- Includes lightweight Ultra-Sil® compression bag, mesh storage cell and laundry bag
- Down: 850+ Loft, 95% European Goose Down
- Fill Weight: Regular: 32.80 oz / 930 grams Long: 35.27 oz / 1000 grams
- Bag Weight: Regular: 3.49 pounds / 1580 grams Long: 3.92 pounds / 1790 grams
- Recommended Max Height: Regular: <6' Long : <6'7"
- Sleeping bag dimensions Internal circumference (Chest, Hip Foot): Regular: 59.84", 51.18", 40.94" Long: 61.42", 53.54", 42.13"
- Temp Rating: Comfort: 16 DegreeF / -9 DegreeC Lower Limit: 5 DegreeF / -15 DegreeC Extreme: -31 DegreeF / -35 DegreeC
- Zipper Option: Long: Left only
- Season Rating: Winter/Extreme
- Suggested Use: Base camp, winter backpacking, snow camping, ski touring, alpine climbing, expeditions
- Compression Bag: Medium - 15L to 5L
Zipper Type: Left Zip
Vendor ProductId: 013RL
Review ProductId: 25322
Interested in some of the more technical elements included in the Sea to Summit Alpine Series of down sleeping bags? Check out our series of blog articles about these sleeping bag features:
3D Sidewall & Reverse Differential Cut
IDFL down fill certification
EN temperature ratings