
Highlights
Best Use: Ultralight Backpacking
Performance: Warm Climate
Weight: 12.8oz | 363g
Compressed Volume: 2.4L
Lower Temp Rating: 45°F | 7°C
Zipper Coupling: Half-Zipper, cannot be zipped to another sleeping bag. Learn more.
Performance
- Ultralight
- Lightweight
- Midweight
- Ultra Compact
- Compact
- Midsize
- Warm
- Cold
- Extreme Cold
About The Product
If you're counting grams, but still count on a great night's sleep, the Spark may be the right bag for you.
Filled with RDS-certified 850+ fillpower goose down treated with a non-PFAS Ultra-Dry Down treatment, the Spark is constructed with a technical hood and zipper draft tube to retain warmth. Comfort comes from a super-breathable 10 Denier liner fabric, while a 10D shell with a non-PFAS DWR plus a highly water repellent hood and footbox fabric shed wind and condensation.
The full-length zipper models can be zipped to an equivalent Women's Spark for comfort that couples can share
Product Features
Shipping & Returns
Free US Shipping on Orders $50+
Easy 60-Day Returns
For more details, please check out our Help Center.
Find Locally
Sea to Summit tests its sleeping bags for their temperature rating using the ISO 23537 test protocol. This test gives two key ratings: Lower Limit and Comfort Rating.
Lower Limit: The lowest temperature at which a man should stay warm.
Comfort Rating: The lowest temperature at which a woman should stay warm.
Sea to Summit Women’s-specific sleeping bags are listed using the Comfort Rating. Unisex bags are listed using the Lower Rating. For example, if the bag is rated at Lower Limit of 14°F | -10°C and Comfort rating of 27°F | -3°C, it should keep a woman warm down to 27°F | -3°C and a man warm down to 14°F | -10°C, if they are wearing warm clothes and using a good sleeping pad.
Remember: These ratings are just guidelines. Movement, weather, and your gear setup can all affect how warm you actually stay.
Pro Tip: Think of your sleeping bag, pad, and liner as a system. If you expect 28°F | -2°C weather, choose a sleeping bag rated for 23°F | -5°C, use a sleeping pad with an R-Value of 3 or more, and add a liner for extra warmth.

Spark Down Sleeping Bag 45°F / Regular

If you're counting grams, but still count on a great night's sleep, the Spark may be the right bag for you.
Filled with RDS-certified 850+ fillpower goose down treated with a non-PFAS Ultra-Dry Down treatment, the Spark is constructed with a technical hood and zipper draft tube to retain warmth. Comfort comes from a super-breathable 10 Denier liner fabric, while a 10D shell with a non-PFAS DWR plus a highly water repellent hood and footbox fabric shed wind and condensation.
The full-length zipper models can be zipped to an equivalent Women's Spark for comfort that couples can share
Design Details
Technical Features

850+ Loft Ultra-Dry Down

Quiltlock System

Responsible Down Standard (RDS)

Non-PFAS
Tech specs
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Best UseUltralight Backpacking
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Comes With40D recycled, bluesign APPROVED nylon compression bag
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InsulationRDS certified, 850+ non-PFAS Ultra-Dry Down
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ShapeMummy
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Zip OptionsYKK #5 zippers with snag free zipper plow
45°F Regular | 45°F Long | 30°F Regular | 30°F Long | 15°F Regular | 15°F Long | 15°F Double | 0°F Regular | 0°F Long | |
---|---|---|---|---|---|---|---|---|---|
Weight | 12.8oz 363g | 13.7oz 387g | 1lb 1.4oz 493g | 1lb 2.9oz 536g | 1lb 9.7oz 730g | 1lb 11.7oz 786g | 3lbs 6.4oz 1543g | 2lbs 7.3oz 1113g | 2lbs 10.5oz 1204g |
Fill Weight | 5.3 oz 150 g | 6.1 oz 172 g | 9.3 oz 265 g | 10.8 oz 305 g | 16.9 oz 480 g | 19.0 oz 540 g | 34.7 oz 985 g | 29.6 oz 840 g | 33.3 oz 945 g |
Compressed Volume | 2.4 L2.4 L | 2.9 L2.9 L | 4.5 L4.5 L | 5.1 L5.1 L | 6.8 L6.8 L | 7.6 L7.6 L | 14.3 L14.3 L | 9.9 L9.9 L | 10.6 L10.6 L |
Compression Sack | 2 L2 L | 3 L3 L | 8 L8 L | 8 L8 L | 13 L13 L | 13 L13 L | 20 L20 L | 20 L20 L | 20 L20 L |
Temperature Rating (ISO Lower Limit) | 45°F 7°C | 45°F 7°C | 30°F -1°C | 30°F -1°C | 15°F -9°C | 15°F -9°C | 15°F -9°C | 0°F -18°C | 0°F -18°C |
Women's Temp Rating (ISO Comfort) | 51°F 11°C | 51°F 11°C | 39°F 4°C | 39°F 4°C | 29°F -2°C | 29°F -2°C | 29°F -2°C | 14°F -10°C | 14°F -10°C |
Fits Up To Height | 6 ft 1 in 185 cm | 6 ft 6 in 198 cm | 6 ft 1 in 185 cm | 6 ft 6 in 198 cm | 6 ft 1 in 185 cm | 6 ft 6 in 198 cm | 6 ft 6 in 198 cm | 6 ft 1 in6 ft 1 in | 6 ft 6 in 198 cm |
Frequently Asked questions
Can I open a Spark flat for use as a quilt?
How much room is there in a Spark?
Can two Sparks be zipped together?
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