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Sea to Summit's Alpine II Down Sleeping Bag is designed to be used in the most extreme of environments. 800g of premium down encased in a waterproof outer is the headline with an array of features to keep you cosy and dry.
Sea to Summit says:
Our Alpine™ Series combines our most technical sleeping bag features to deliver reliable performance while cocooning you in the highest quality RDS 850+ Loft Goose ULTRA-DRY Down™.
Designed for high altitude mountaineering and arctic conditions, the contoured mummy design delivers efficient insulation, while our updated expedition sizing provides space for extra clothing to be worn inside the bag. The anatomically shaped and oversized footbox can comfortably accommodate boots when necessary.
Vertical baffles over the chest section ensure the down insulation cannot migrate or shift to the outside of the bag during sleep, creating cold spots. A side block baffle construction maintains the 60/40 fill ratio, keeping more down on the top of the bag for maximum insulation.
Our ULTRA-DRY Down™ water-repellent treatment protects the down from external moisture and condensation from the inside of the bag, virtually eliminating the negative effects moisture has on down. All Sea to Summit Down Sleeping Bags use Responsible Down Standard (RDS) certified down.
The Free-Flow Zip system provides a half zip on the right side of the bag to provide freedom of movement for both arms as well as additional ventilation. The full length, two-way left side zip provides easy access and extra ventilation options.
Our waterproof yet breathable NanoShell™ fabric provides protection from wind and moisture. The tightly sized and carefully panelled hood fits snugly around your head, allowing you to maintain maximum warmth with minimal adjustment.
An oversized zipper draft tube is fitted with the lightest and stiffest anti-snag materials for effortless operation and to prevent heat loss through the zipper.
Our Verdict
Sea to Summit's Alpine II Down Sleeping Bag is a premium bag for serious environments. Everything about this bag is is designed to keep you warm and dry in the harshest of conditions using the highest quality materials.
Unlike other bags moisture is not a concern with this bag thanks to the water proof Nanoshell outer. The responsibly sourced and super high quality 850+ fill power is dry treated so will retain its warmth if wet far better than none treated down. 800g of is a lot of insulation hence the -20°C Comfort Limit rating.
The bag is roomy giving you plenty of wriggle room and/or the ability to layer in the bag if required. There are plenty of venting options with a full length left hand zip and half length 2 way right hand zip. These also make it easy to get in and out of when your exhausted and cold. Both zips have massive baffles to make sure there is no heat loss.
Around the head is a snug hood and generous draft tubes to reduce heat loss. Drawcord adjustment to ensure the snuggest of fits. At the other end the footbox is big enough to fit boots so you don't have the agony of trying to force your feet into frozen boots in the morning.
- Reviewed by BasecampGear
Features
- Designed for extreme cold and high-altitude conditions
- Contoured mummy shape for efficient insulation
- Expedition sizing for extra space and layered clothing
- Vertical chest baffles prevent down migration and cold spots
- Side block baffle with 60/40 fill ratio keeps more down on the top of the bag for maximum insulation
- Anatomically shaped and oversized footbox can accommodate boots
- Free-Flow half right-side zip for freedom of movement and additional ventilation
- RDS 850+ Loft Premium Goose ULTRA-DRY Down™ for maximum insulation value
- Our waterproof/breathable NanoShell™ fabric protects against wind and moisture
- Snug panelled hood maintains maximum warmth with minimal adjustment
- Oversized draft tube with anti-snag materials, prevents heat loss through zipper
- Oversized neck draft tube with a dual adjustment system for even cinching and maximum warmth
- YKK #5 side zip has two sliders for easy access and extra ventilation
- Large internal security pocket
- Includes lightweight Ultra-Sil™ compression bag for compact storage
- NOTE: This bag is not designed to pair with another
Specifications
Temperature Rating
- EN13537:2012 Comfort: -12°C / 10°F
- EN13537:2012 Comfort Limit: -20°C / -4°F
- EN13537:2012 Extreme: -42°C / -44°F
Regular Specs
- Weight: 1318g (excludes storage bags)
- Fill weight: 800g
- Fits up to: 6 ft / 183 cm
- Internal Width Shoulder: 160cm / 63 in
- Internal Width Waist: 142cm / 56 in
- Internal Width Feet: 131cm / 51.5 in
Materials
- Insulation: RDS 850+ Loft Premium Goose ULTRA-DRY Down
- Shell: Water repellent NanoShell
- Zipper: Left-side #5 YKK zipper
- Comes with: Ultra-Sil™ compression bag and storage cell
