Take bold risks and conquer the elements with the unbeatable 4-season Sea to Summit Spark Down Sleeping Bag -18°C. With precise engineering and top-quality materials, this compressible bag offers unmatched warmth, empowering you to push boundaries. Perfect for the daring adventurer seeking a featherlight experience, the Spark can also work with the female version for a double bag setup or with a Sea to Summit quilt to provide extra insulation during frigid solo nights.

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

Pair up your Sea to Summit sleeping bag with a compatible liner for the ultimate sleep system.

More Help? For further assistance on choosing your down sleeping bag, we have an article explaining fill power, the pros and cons of down over synthetic insulation and more info on caring for your bag available to view here: .

• 850 FILL Power, RDS-certified, Goose Down with Ultra Dry Down treatment for improved water resistance in damp conditions.
  
• 10-Denier Nylon shell and lining. 10-Denier Nylon waterproof-breathable hood and footbox.
  
• Mummy Fit: Fitted cut with generous footbox and technical hood, to maximise thermal efficiency and minimise bulk and weight.
  
• Spark 7C/45F & 1C/30F Primary zip - 1/2 length #5 with zip-plow and two sliders. Spark -9C/15F & -18C/0F Primary zip - 3/4 length #5 with zip-plow and two sliders.
  
• Vertical chest baffles, horizontal baffles lower half and base. SPARK 7C sewn through quilted construction throughout. SPARK -1C/30Fbox wall baffles top half of bag and sewn through quilted construction lower half. SPARK -9C & -18C box wall baffle construction throughout.
  
• Spark 7C, -1C & -9C Standard front draft collar. SPARK -18C Double draft collars.
  
• Spark 7 & -1 can't be paired. Spark -9 & -18: Pairs with Women's Sea to Summit bags.
  
• QuiltLock System integrates with StS quilts.
• Draft tube

• Maximum User Height:  Regular: 185cm /  - Long: 198cm
• Comfort Temperature: -10°C
• Comfort Temperature limit:  -18°C
• Shoulder width:  Regular: 155cm / Long: 165cm
• Waist With: Regular: 135cm / Long: 145cm
• Foot box width:  Regular: 102cm / Long: 112cm
• Insulated collar: Yes
• Shell Fabric: 10-Denier Nylon shell and lining. 10-Denier Nylon waterproof-breathable hood and footbox. Nylon waterproof-breathable hood and footbox.
• Filling: Ultra-Dry goose down
• Fill power: 850
• Weight: Regular: 730g / Long: 786g
• Fill Weight: Regular: 1113g / Long: 1204g
• Compression Size: 20L
• Zip: Left
• Draft tube