Sea to Summit Traverse XT II


spring 2010 short regular long
Weight 2 lb 8 oz / 1140 g 2 lb 11 oz / 1210 g 2 lb 15 oz / 1340 g
Fill weight 1 lb 2 oz / 520 g 1 lb 3 oz / 540 g 1 lb 4 oz / 580 g
EN comfort 23 F / -5 C
EN lower limit 12 F / -11 C
EN extreme -22 F / -30 C
Fill 850-fill down
Shape Mummy
Max user height 5 ft 7 in / 170 cm 6 ft 0 in / 185 cm 6 ft 8 in / 205 cm
Shoulder girth 57 in / 146 cm 59 in / 150 cm 61 in / 156 cm
Hip girth 51 in / 130 cm 54 in / 138 cm 57 in / 144 cm
Foot girth 38 in / 97 cm 41 in / 104 cm 42 in / 107 cm

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Brilliant technical features that just work. If you…

Rating: rated 5 of 5 stars
Source: bought it new
Price Paid: $500 (US)


Brilliant technical features that just work. If you look at the manufacturer's specs, you can see that this bag is, in its class, just about the most technically advanced bag in the world. I tried mine out last weekend and the expectations were completely met with perfect build quality.


  • Waterproofness: both water repellant coating, synthetic down outer, and treated down inner
  • Comfort
  • Zips work snag free, better than some of my other bags!


  • Nothing I can think of

The hood worked well. The lofting was excellent. I have owned four bags for different temps and conditions. I should have just bought this one bag. You can snug it up for snow and cold. You can partially unzip the sides for warmer temps.

You can also totally unzip the side and the foot region to turn it into 2 dooners. The back and the front have different thicknesses of down so you get a choice of 2 dooners.

The outer has hydrophobic nano particles to act  as permanent water repellants. Inside the first layer you have layer of synthetic down so if any water gets in it will still not affect the insulation very much.

Then inside a second layer you have treated goose down with 850 loft. This treated down works better than natural down in wet conditions — it too is treated. So you have three levels of water protection, which is great for me since my previous bags had none!

This bag was not sweaty at all — a common problem with waterproof bags. In fact it was less sweaty than a bag without any waterproofing but with the same temperature rating.

Overall: Probably the best bag in its class in the world: Highly, highly recommended. Hence 5 stars!

Update May 2015:

Just back from a second trip. The bag stayed warm and dry. It was not clammy or sweaty, just nice. This time I teamed it up with a Sea to Summit Comfort Light Insulated pump-up mattress. The pump is a Sea to Summit Jet Stream Pump Sack and also works with the Sea to Summit Aeros inflatable pillow.

The whole system worked like a dream. Best night's sleep I think I have ever had (in 30 years). Temp in the morning was around -10°C.


Thanks for the review. Please update us if your opinion changes with continued use.

9 months ago

Thanks for the update, denevans. Perhaps you'll want to share a review of your Jet Stream and Comfort Light Insulatd mat sometime too.

7 months ago
Denis Evans

Have submitted a review of the Comfort Light Insulated mat and the associated pillow - separately.

7 months ago

Thanks for sharing your Aeros pillow review too: Also, I wanted to let you know that I didn't see a Comfort Light Insulated one (feel free to PM me if I'm missing something here):

7 months ago

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