Camping & Hiking expert Amy recommended it to a customer 16 days ago
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Sea to Summit Spark SpIII 18 · Gray/Yellow

Sea to Summit Spark SpIII 18 · Gray/Yellow

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Color: Gray/Yellow
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Product details

An ultralight and highly compressible down bag made for both men and women, the SpIII is a high-performing choice for backpackers, climbers, cyclists, and other adventurers with a lower-limit warmth rating of 18 F. It’s part of Sea to Summit’s Spark™ Series, which spans from an ultralight liner to an expedition weight mid-winter bag, and offers an exceptional warmth-to-weight ratio with 850-fill, water-repelling ULTRA-DRY Down™. Key Features: - Highly Compressible – The Spark III compresses to the size of a hand with the help of the included lightweight Ultra-Sil™ Nano compression bag.

  • Contoured Mummy Shape – The mummy-style makes for efficient insulation, while the fit has been updated to provide more wiggle room or space for layered clothing, particularly around the shoulders and hips.
  • 850+ Fill Power – The high loft of this bag’s down insulation keeps it lightweight yet incredibly warm in temperatures around 20 degrees, and it fends off external moisture and internal condensation with ULTRA-DRY Down™ water-repelling treatment.
Temperature rating
18° F
Intended use
Fill type
1 lb. 8 oz.
Sleeping capacity
Ultra-Dry Down 850+ Loft
Age Group
Is ultralight
Tested lower limit
18° F
Tested comfort
29° F
Ultralight 10D Nylon Shell
Shoulder girth
61 in.
Hip girth
53 in.
Stuff sack size
6 x 14 in
Fits up to
72 in
Compressed volume
Sea to Summit Spark SpIII 18 · Gray/Yellow
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Top reviews
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Amy B
Amy B
Verified camping & hiking expert
Reviewed Aug 13, 2022

Ultra dry 850-fill down insulation makes this bag warm, lightweight and very packable. It includes a compression sack and storage bag.

Correy Johnston
Correy Johnston
Verified camping & hiking expert
Reviewed Aug 13, 2022

Keeping you warm head to toe with a mummy design. Being one of the lightest bags out there it has a 850-fill down which is near the top of the market.