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Sea to Summit Spark SP1 5°C Ultra Light Down Sleeping Bag - Regular Length

Sea to Summit

Sale price $424.15 Regular price $499.00

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Ultra-light and technical, the Sea to Summit Spark™ Series bags are designed to keep you as warm as possible while minimising packed weight and size.

The Spark™ Series spans everything from an ultralight liner to an expedition weight mid-winter bag. While the end usage is very different, they reflect a design ethos of matching weather conditions to the lightest bag possible.

The secret to the impressive performance is a combination of premium materials and careful design. The RDS 850+ Loft premium goose down, light-gauge #3 YKK zip and high performance 10D Nylon shell and 7D lining fabrics, set the stage for superior performance. These materials are combined with a contoured mummy design for efficient insulation, and that mummy design is then tweaked for each model to best fit the use scenario.

ULTRA-DRY Down™ water-repellent treatment protects the down from external moisture and condensation from the inside of the bag, virtually eliminating the negative effects moisture has on down. All Sea to Summit Down Sleeping Bags use Responsible Down Standard (RDS) certified down. The ULTRADRY Down™ protection also makes the Spark™ an impressive hard-alpine or adventure racing bag, where every gram is counted and down has never been a viable option.


  • Ultralight 7D and 10D fabrics for minimal weight and packed size
    RDS 850+ Loft Premium Goose ULTRA-DRY Down™ for maximum insulation value
  • Contoured mummy shape for comfort and efficient insulation
  • Vertical chest baffles prevent down migration and cold spots
  • Sewn through construction minimises weight
  • Sewn through vertical baffles on chest optimises position of down to prevent it moving during use
  • ½ zip with single slider aids access while keeping weight to a minimum
  • Updated sizing provides extra room for both shoulders and hips while still maintaining insulation efficiency
  • Includes lightweight Ultra-Sil™ Nano compression bag for compact storage
  • Shell: 100% Nylon, Lining: 100% Nylon, Primary Filling Material: GOOSE DOWN (Min. 90% Down), Stuffsack: 100% Nylon excluding Trims


Down Type RDS Ultra Dry 850+ Loft European Goose Down for maximum insulation value
Fill Weight Regular: 180g 
Sleeping Bag Weight Regular: 340g
Baffle Design Sewn through construction minimises weight
Shell Design

Contoured mummy shape for comfort and efficient insulation

Vertical chest baffles prevents down from shifting off chest

Outer Shell Fabric ultralight 7D and 10D fabrics for minimal weight and pack size
Recommended height for user Regular - up to 183 cm high
Chest circumference Regular - 150 cm
Hip circumference Regular - 130 cm
Foot circumference Regular - 88 cm
Season Rating Indoor / Summer / Spring / Autumn
EN Temperature Rating Comfort: 9°C Lower Limit: 5°C Extreme: -9°C
Suggested Use Travel, adventure racing, summer cycle touring, liner bag, ultra lightweight hiking, ultra lightweight alpine climbing
Compressed Volume 1.55 Litres
Compression Bag 2XS - 2.5 to 1.0 Litres

Additional Information

The Spark is an ultra light bag with several key uses. Its balance of size, weight and warmth make it excellent as a summer sleeping bag, especially for weight and space conscious cycle tourers and ultra light walkers. Its size and warmth rating works well as a liner bag, slipping inside another sleeping bag to add one or two seasons to its rating.

The secret to the Spark’s warmth to weight are in the premium quality down and high performance microweight shell and liner fabrics, the 1/3 length light-gauge #3 YKK zip and the sewn-through transverse baffle construction.

The Spark compresses so small, Sea to Summit had to re-engineer their compression-sacks to make one that reduced sufficiently. The ULTRA-DRY Down™ protection makes the Spark an impressive hard-alpine or adventure racing sleeping bag, where down has never before been a viable option, and weight is simply not tolerated.

1/3 Zip Mummy Bag
The Spark is cut as a close-fitting mummy bag. The full hood, foot box and short zip maximise fit and warmth while keeping weight and bulk to a minimum.