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  • Sea To Summit - Spark SpII Sleeping Bag: 35 Degree Down -
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  • Sea To Summit - Spark SpII Sleeping Bag: 35 Degree Down -

Sea To Summit Spark SpII Sleeping Bag: 35 Degree Down

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2 Reviews


Ultralight, highly compressible, and extremely protective.

The Sea to Summit Spark SpII Sleeping Bag is ultralight for backpackers, racers, bicyclers, and alpine climbers. Primarily focusing on giving you the lightest bag out there, Sea to Summit stuffed the Spark with 850-fill down for the best possible warmth-to-weight ratio. This bag's nylon shell is windproof and prevents the down from breaking through, and the smooth nylon lining adds some durability. Going beyond an ultralight design, Sea to Summit added its Ultra-Dry Down treatment to help this bag resist moisture and enhance your comfort regardless of the conditions.

The Spark SpII has a contoured mummy shape to closely fit your body while you sleep. Its full hood wraps around your head to eliminate the possibility of waking up with freezing ears, and the 1/3-length zipper on the left helps maximize warmth. The Spark compresses so small that Sea to Summit had to re-engineer a new compression sack for it, ending up with a sack that can fit in the palm of your hand. So when you get this bag, you might be able to stuff your pack with a few extras even if you are a minimalist.

  • 44°F EN comfort rating
  • Ultra-Dry Down 850+ insulation
  • Mummy shape
  • 10D UL nylon shell, 15D nylon lining
  • Full hood
  • 1/3-length zipper on left side
  • Ultralight: 1 lb .4 oz
  • Compression sack included
  • Item #STS000G

Tech Specs

[shell] 10D nylon, [lining] 15D nylon
850+ fill goose down
Max User Height
[regular] 6 ft, [long] 6 ft 7 in
Shoulder Circumference
[regular] 57 in, [long] 60 in
Hip Circumference
[regular] 50 in, [long] 52 in
Foot Circumference
[regular] 35 in, [long] 37 in
Fill Weight
[regular] 9.9 oz, [long] 10.8 oz
European Norm Comfort Rating
European Norm Lower Limit Rating
Stuff Sack
Stuff Size
[compression volume] 2.9 L
Claimed Weight
[regular] 1 lb .4 oz, [long] 1 lb 2 oz
Recommended Use
backpacking, camping
Manufacturer Warranty

Tech Specs

  • Reviews
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The bag is really a lightweight

  • Familiarity: I've put it through the wringer

this is the lightest bag on the market. so if you are all about weight (which I personally am) then this is a great bag. It is not the warmest, but I've had it in the Tetons, the Sierra Nevada Mtns, the Grand Canyon, and many other local areas. I have never been disappointed. IN the fall, I do have to sleep in my thin down coat that I always bring with me. The only downside is the zipper is only a 1/2 zip. It doesn't unzip all the way. I personally cut my zipper out and re-sewed my bag to be an open quilt. so now it is even lighter. Again, this bag will do 35 to 40 if you wear a fleece. It is not the ultimate construction or warmth, but I love it for it's weight. great bag if you're all about weight.

Horrible - don't do it

  • Familiarity: I've used it several times

This bag was a huge disappointment. I used it in the summer in Alaska and then in Colorado. I was absolutely freezing in it all night long. And if your wondering, I wear fleece pants, fleece top and thick socks in sleeping bags so I wasn't nude. I ended up using an extra blanket I happened to have with me to make it through the nights in Colorado. Also the zipper only goes down a couple feet so you have to shimmy into it which means everything in your small tent is upside down and a mess when your getting in and out of it. Going to the bathroom in the night was frustrating because of that. The upside is it is very small and ultralight. But so not worth it. The temp. rating on it is not accurate. I was camping in 40-50 degree weather at night and it was VERY cold. They need to change the design so its a LOT warmer and make the zipper go the length