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Spark™ Ultralight Sleeping Bag

FIVE VERSIONS for performance in any season

$229.00 – $549.00

Sleeping Bag Temperature Ratings Explained

The EN Rating scale is a scientific test to determine the warmth of a sleeping bag. The test produces a Lower rating (for male sleepers) and a Comfort rating (for female sleepers). Both are listed in the features table on the product page.

A unisex sleeping bag with a Lower limit of 23ºF means a man should be comfortable down to air temperatures of 23ºF. The same bag will also have a Comfort limit, in the realm of 32°F, so a woman would be comfortable down to an air temperature of 32ºF. These ratings require a sleeping mat with an R-Value appropriate for expected ground temperatures – without this, the sleeping bag itself is unlikely to keep the sleeper warm enough.

A variety of factors impact sleeping bag warmth - the above temperatures are merely guidelines, not guarantees. It’s important to think of a sleeping bag, an appropriately insulating sleeping pad and a liner as a sleep system. For example - if you plan on sleeping in nighttime air temperatures of 27ºF / -3°C, choose a bag with a gender-appropriate rating of 23°F / -5°C, plus a sleeping mat with an R-Value of 2.5 to 3, and consider a Reactor thermal liner.

$299.00
Description

The Spark™ Ultralight Sleeping Bag Series spans everything from an ultralight down-filled liner to a mid-winter fast-and-light sleeping bag. Each model uses premium materials and no-frills design to provide cutting-edge performance for the designed end-use.

Ultralight does not mean ultra-tight: The Spark sleeping bags are snug but still have adequate girth for the performance-oriented backcountry user.

Is this down sleeping bag…?

  • Suitable for cooler temperatures? Yes. You would want the Spark 5°F or possibly the 18°F – either bag will work in late Fall, the 5°F will take you down to winter temperatures when paired with an adequately insulating sleeping mat like the Comfort Light Insulated.

  • Really suitable as a sleeping bag liner? Yes. You could use the Spark 50°F, or even the Spark 40°F or 28°F to boost the performance of a bag for cold-weather use. Adding one of these to a 20°F / -5°C bag might make more sense than buying a “0°F / -20°C” bag for only occasional winter use.

  • Able to be zipped to another sleeping bag? No. Even though the 18°F or 5°F have full-length side zippers, they are not designed to be coupled to a sleeping bag with a right zipper (for instance the Flame 18°F or 5°F).

Read up on the factors which define and affect down quality, and what they mean for you as an end user HERE 

Highlights

Best Use

  • Ultralight Backpacking, Bike Touring, Liner Bag

Performance

  • Summer or Sleeping Bag Liner: 50°F  (comfort range 50°F to 70°F)
  • Warm weather: 40°F (comfort range 40° to 60°F)
  • 2 Season: 28°F (comfort range 28°F to 60°F)
  • 2.5 Season: 18°F (comfort range 18°F to 55°F)
  • 3.5 Season: 5°F (comfort range 5°F to 50°F)

FEATURES

  • ULTRA-DRY Down 850+ Loft 90% Down Cluster Premium Goose Down certified Responsible Down Standard (RDS)
  • 10D shell and 7D liner materials help to achieve the incredible lightweight and compact packed size
  • Includes lightweight Ultra-Sil™ compression bag and storage cell
  • Zipper-length trimmed for gram-saving performance
    • 50°F, 40°F, and 28°F have 1/3-length zippers
    • 18°F and 5°F have full-length side zippers
  • Baffle construction
    • 50°F and 40°F have sewn-through construction.
    • 28°F has baffles in the torso and sewn through in the leg area.
    • 18°F and 5°F are fully baffled.

Technical Features

850+ Loft Ultra-Dry Down™

The highest-lofting down used in any of Sea to Summit’s sleeping bags. 850+ Fill Power indicates that one ounce (30g) of down will re-expand to over 850 cubic inches after compression. Higher loft means that less down can be used to achieve the same temperature rating – important for performance sleeping bags. The loft and down quality/composition are independently tested by the International Down and Feather Laboratory (IDFL) – a copy of the certification is supplied with every Sea to Summit sleeping bag.

 

The down is responsibly sourced and RDS certified and treated with the environmentally-friendly Ultra-Dry Down™ treatment.

 

All of which means you can rest easy.

Responsible Down Standard (RDS)

All Sea to Summit sleeping bags use only down which is certified according to the Responsible Down Standard. The RDS is helping shift the entire down and feather industry towards more humane animal rearing and handling practices. Overseen by the industry leading Textile Exchange, the RDS requires independent, third-party assessments of all aspects of animal rearing and handling throughout the entire supply chain. By using only down that meets the audited requirements of the RDS, we can have confidence that each phase of the collection process has been completed with the welfare and ethical treatment of waterfowl in mind.

To learn more about RDS, visit responsibledown.org

UL 10 Denier Nylon

Despite being incredibly lightweight, the 10 Denier UL Nylon is down-proof and surprisingly durable. A DWR finish helps to shed external moisture. This fabric is part of the secret to making the Spark and Flame Down Sleeping Bag Series some of the lightest, most packable sleeping bags available today.

Tech Specs

Product Details

Best Use
Ultralight Backpacking
Comes With
Ultra-Sil™ compression bag and storage cell
Insulation
Ultra-Dry Down 850+ Loft
Shell Fabric
Ultralight 10D Nylon Shell
Zip Options
Left-side #3 YKK zipper
 
40°F REGULAR
40°F LONG
28°F REGULAR
28°F LONG
18°F REGULAR
18°F LONG
5°F REGULAR
5°F LONG
LINER REGULAR
LINER LONG
BAG SERIES
BAG WEIGHT
COMPRESSED VOLUME (ASTM STD)
COMPRESSION SACK
FILL WEIGHT
FITS UP TO
SEASON RATING
TEMPERATURE (EN RATING)
WOMEN'S TEMP (EN RATING)
Spark 1
12oz / 340g
1.5 L
XXXS - 2.5L to 1L
6.3oz / 180g
6 ft / 183 cm
Warm Weather
Comfort range 40° to 60°F
44ºF (Comfort)
Spark 1
13.6oz / 385g
2.2 L
XXXS - 2.5L to 1L
7.2oz / 205g
6 ft 4 in / 192 cm
Warm Weather
Comfort range 40° to 60°F
44ºF (Comfort)
Spark 2
1lb 1.3oz / 490g
2.5 L
XXS - 3.3L to 1.3L
10.6oz / 300g
6 ft / 183 cm
2 Season
Comfort range 28°F to 60°F
35ºF (Comfort)
Spark 2
1lb 3.8oz / 560g
3.5 L
XXS - 3.3L to 1.3L
12.2oz / 345g
6 ft 4 in / 192 cm
2 Season
Comfort range 28°F to 60°F
35ºF (Comfort)
Spark 3
1lb 7.5oz /665g
4.6 L
XS - 6L to 2L
15.2oz / 430g
6 ft / 183 cm
2.5 Season
Comfort range 18°F to 55°F
29ºF (Comfort)
Spark 3
1lb 10.3oz / 745g
5.4 L
XS - 6L to 2L
17.1oz / 485g
6 ft 4 in / 192 cm
2.5 Season
comfort range 18°F to 55°F
29ºF (Comfort)
Spark 4
1lb 15oz / 880g
6.6 L
S - 10L to 3.3L
21.9 oz / 620g
6 ft / 183 cm
3.5 Season
Comfort range 5°F to 50°F
18ºF (Comfort)
Spark 4
2lbs 2.7oz / 985g
7.7 L
S - 10L to 3.3L
24.7oz / 700g
6 ft 4 in / 192 cm
3.5 Season
Comfort range 5°F to 50°F
18ºF (Comfort)
Spark 0
7.9oz / 225g
.9 L
N/A
3.5oz / 100g
6 ft / 183 cm
Summer or Sleeping Bag Liner
Comfort range 50°F to 70°F
54ºF (Comfort)
Spark 0
9.2oz / 260g
1.3 L
N/A
4.1oz / 115g
6 ft 4 in / 192 cm
Summer or Sleeping Bag Liner
Comfort range 50°F to 70°F
54ºF (Comfort)

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