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Sea To Summit
Spark SpI Sleeping Bag: 40F Down

4.631578947368421 out of 5 stars
152 Reviews

Out of Stock

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Spark SpI Sleeping Bag: 40 Degree Down

Weighing only 12 ounces, the Sea to Summit Spark Spl Sleeping Bag brings the comfort without the weight whether you're an ultralight backpacker, an adventure racer, a touring bicycler, or an alpine climber. Primarily focusing on giving you the lightest bag out there, Sea to Summit stuffed the Spark Spl with 850+ down for the best possible warmth-to-weight ratio that can still keep you nice and toasty in temps down to 45F. Going beyond just being ultralight, Sea to Summit's Ultra-Dry Down treatment also helps this bag resist moisture to enhance your comfort regardless of the conditions.


The Spark Spl 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 1/2-length zipper on the left helps maximize warmth when the temps drop. If you find yourself in colder conditions, the SpI can be utilized as an ultralight sleeping bag liner in another sleeping bag to keep you warmer through high alpine treks or winter camping. Finally, the Spark compresses small so you're able to stuff your pack with a few extras even if you are a minimalist.


Details

  • Versatile, compact, and lightweight performance sleeping bag
  • Contoured mummy shape delivers comfort and efficient insulation
  • Warm Ultra-Dry Down insulates even when you're in wet conditions
  • Light shell fabric compresses down small for efficient packing
  • Vertical chest baffles prevent down migration to warm your core
  • 1/2-lengh zipper allows easy access while keeping weight down
  • Lightweight design allows use as a liner in colder conditions
  • Sea to Summit focuses on comfortable and lightweight products
  • Item #STS006Y
Material
[face fabric] 10D nylon, [lining] 7D nylon
Insulation
RDS 850+ Loft Premium Goose Ultra-Dry Down
Shape
contoured mummy
Zipper
1/2-zipper
Max User Height
[regular] 6ft, [long] 6ft 4in
Shoulder Circumference
[regular] 59in, [long] 62in
Hip Circumference
[regular] 51in, [long] 54in
Foot Circumference
[regular] 35in, [long] 38in
Bag Length
[regular] 6ft, [long] 6ft 6in
Pockets
none
Pad Retainer
no
Venting
2-way zipper
Fill Weight
[regular] 6.3oz, [long] 7.2oz
Degree
40F
European Norm/ISO Comfort Rating
48ºF
European Norm/ISO Lower Limit Rating
40ºF
Storage Sack
storage cell
Stuff Sack
Ultra-Sil compression bag
Stuff Size
15 x 8in
Claimed Weight
[regular] 12oz, [long] 13.6oz
Manufacturer Warranty
lifetime

Overall Rating

4.5 based on 152 ratings

Review Summary

1 Stars - 4 reviews
2 Stars - 2 reviews
3 Stars - 6 reviews
4 Stars - 22 reviews
5 Stars - 118 reviews

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5 out of 5 stars

March 19, 2024

Great bag!

[This review was collected as part of a promotion.] Very lightweight and compact bag, and very comfortable and warm.

Samuel C.
Sea to Summit

Originally reviewed on Sea to Summit

5 out of 5 stars

March 4, 2024

Great sleeping bag. Light weight,

[This review was collected as part of a promotion.] Great sleeping bag. Light weight, but warm. I used it this past weekend with the temp down to 31 degrees and was very comfortable. Highly recommend.

William J.
Sea to Summit

Originally reviewed on Sea to Summit

5 out of 5 stars

March 4, 2024

Amazing sleeping bag

[This review was collected as part of a promotion.] Lightweight, down certification, great size. Loving the sleeping bag. Only down side is what happened to the big cotton storage sacks? Now it is a tiny plastic zip bag they give you that you have to stuff the bag into. That does not seem like a good storage sack that should let your sleeping bag breath and be fluffy. Bring them back! Disappointed that it no longer comes with the bag.

Pavla M.
Sea to Summit

Originally reviewed on Sea to Summit

5 out of 5 stars

March 2, 2024

Very light bag. Yet roomy.

[This review was collected as part of a promotion.] Though I have not used the bag yet, I love how light it is and how small it compresses

Thomas M.
Sea to Summit

Originally reviewed on Sea to Summit

5 out of 5 stars

March 2, 2024

Great Sleeping Bag

[This review was collected as part of a promotion.] Got this bag and immediately ended up on 2 campouts below freezing. Bag worked great and made me realize how my older bags are not as warm as they use to be. The storage bag and compression sack are very helpful for packing and storing the bag. The only flaw with this sleeping bag is that my kids love it and have claimed it for themselves, so I don't get to use it as often as I normally would.

Joseph H.
Sea to Summit

Originally reviewed on Sea to Summit

5 out of 5 stars

February 11, 2024

Super lightweight and great quality

[This review was collected as part of a promotion.] The sleeping bag has really impressed me. Super lightweight, very small when packed into compression bag. Quality in every detail. The only cons, while understandable, is rather short zipper. Making it a bit longer would make it easier to get in and out

Volodymyr O.
Sea to Summit

Originally reviewed on Sea to Summit

5 out of 5 stars

January 23, 2024

This sleeping bag is exactly

[This review was collected as part of a promotion.] This sleeping bag is exactly what I was looking for. Lightweight and perfect for cooler nights hunting in November and December. This will be used for bikepacking trips as well of course.

Kyle H.
Sea to Summit

Originally reviewed on Sea to Summit

4 out of 5 stars

January 8, 2024

Good bag, mediocre zipper?

[This review was collected as part of a promotion.] Zipper pull came out on the first use so returning it.

Vishal A.
Sea to Summit

Originally reviewed on Sea to Summit

2 out of 5 stars

January 5, 2024

Light but not great

I purchased the Spark 5 degree down bag and was excited at first. The bag weighed about an ounce less than the specifications, which was awesome until I looked closer. There is not enough down to have it spread out throughout the bag any any thickness. It has too many blank spots. Every time it is adjusted the down has to come from somewhere else. I suspect this bag was shorted on down. My other brand 25 degree bag is warmer. The zipper is very frustrating, it requires very specific angles to work and is very light duty, not much fun in the middle of the night. It is the wimpiest zipper I have ever seen on a sleeping bag. The bag is light and good to about 30 degrees compared to other bags.

Mike
Sea to Summit

Originally reviewed on Sea to Summit

4 out of 5 stars

December 29, 2023

Hard to beat the spark for ultralight!

[This review was collected as part of a promotion.] I really like the Spark Bag and it's weight is amazing. I'd give it five stars if it was just a bit roomier but i guess for an ultralight bag I shouldn't be expecting it to be roomier. I'd buy again.

Bradley D.
Sea to Summit

Originally reviewed on Sea to Summit