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Sea to Summit
XT II 12° F Sleeping Bag

Out of Stock  Product Number: 25330

  • Price:
    $528.95 -  $568.95
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The Sea to Summit XT II 12 degree sleeping bag is the warmest bag in the Traverse Series, versatile down sleeping bags designed for a variety of activities. This sleeping bag is EN-rated to a lower-limit temperature of 12 degrees F and a comfort temperature of 23 degrees F.

The Traverse Series down sleeping bags offer comfort in a wide range of temperatures. 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. The patent-pending 3D NanoShell™ technology repels external moisture and keeps condensation away from the down insulation. Innovations like the 3D Sidewall and Reverse Differential Cut keep that 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 relaxed mummy fit and separate foot zip, the XT II can be unzipped into a full duvet for sleeping in huts or closed tight for winter camping in sub-freezing conditions. 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 ensures smooth zipper operation. An easily-accessible security pocket inside the bag is ideal for stowing electronics in extreme cold.

The Traverse Series is Sea to Summit’s choice for trekking the Annapurna circuit in the Himalayas, ski touring hut-to-hut in the Alps and walking the Western Arthurs in Tasmania. 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.


  • Relaxed mummy convertible, 3D NanoShell™
  • Differential cut shell with 3D side walls
  • Offset baffles,
  • 60/40 fill ratio
  • Side block baffle
  • Anatomically tapered foot
  • Zip draft tube with anti-snag
  • Neck draft tube with dual elastic adjustment
  • Cushioned internal hood drawcord with dual adjustment
  • 2 way YKK #5 zips with separate foot 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: Short: 18.34 oz / 520 grams Regular: 19.05 oz / 540 grams Long: 20.46 oz / 580 grams
  • Bag Weight: Short: 2.51 pounds / 1140 grams Regular: 2.67 pounds / 1210 grams Long: 2.93 pounds / 1340 grams
  • Recommended Max Height: Short:<5' 5" Regular: <6' Long : <6'7"
  • Sleeping bag dimensions Internal circumference (Chest, Hip Foot): Short: 57.48", 51.18", 38.19" Regular: 59.05", 54.33", 40.94" Long: 61.42", 56.69", 42.13"
  • Temp Rating: Comfort: 23 Degree F/ 5 Degree C Lower Limit: 12 Degree F/ 11 Degree C Extreme: -22 Degree F/ -30 Degree C
  • Zipper Option: Short: Right only Regular: Left or Right Long: Left only
  • Season Rating: Spring/Autumn/Winter
  • Suggested Use: Lightweight backpacking, hiking, snow camping, ski touring, base camp
  • Compression Bag: Medium - 15L to 5L

Gender: Unisex
Zipper Type: Left Zip
Season: F13
Vendor ProductId: 022LL
Review ProductId: 25330

Interested in some of the more technical elements included in the Sea to Summit Traverse Series of down sleeping bags? Check out our series of blog articles about these sleeping bag features:

3D NanoShell
3D Sidewall & Reverse Differential Cut
IDFL down fill certification
EN temperature ratings

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