Sea to Summit Spark Ultralight 28F Sleeping Bag

$409.00to $429.00
Color: Dark Grey/Yellow
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Designed to keep you as warm as possible while minimizing packed weight and size, the Sea to Summit Spark Ultralight 28F sleeping bag is lightweight and technical for your industrious adventures.

  • Features

    • Super lightweight 7-denier and 10-denier fabrics offer minimal weight and packed size
    • 850+ fill-power Premium Goose UltraDry Down™ is certified to the Responsible Down Standard (RDS) and provides maximum insulation value
    • Contoured mummy shape provides comfort and efficient insulation
    • Vertical chest baffles prevent down migration
    • Note: This bag is not designed to zip with another
    • Includes lightweight Ultra-Sil™ compression bag and storage cell


    Many sleeping bags are rated for temperature by an independent testing protocol. REI and the broader industry now use the International Organization for Standardization (ISO) 23537 protocol, which improves on the older European Norm (EN) 13537 standard; you may still see older items in our assortment that were only EN tested. With either protocol, each bag gets a Comfort (or T-Comfort) rating and Lower Limit (or T-Limit) rating. The Comfort rating is the lowest temperature at which the bag will keep the average "cold sleeper" comfortable, and the Lower Limit rating is the lowest temperature at which the bag will keep the average "warm sleeper" comfortable. Ratings are based on a person wearing one long underwear layer and a pair of socks, sleeping on an insulated surface with a minimum R-value of 5.38. Many brands use the Comfort rating for women's bags and the Lower Limit rating for men's and unisex bags. Everyone's body and sleep comfort differ, and conditions of use (posture, clothing, sleeping pad R-value, wind, humidity, etc.) affect total insulation, so EN and ISO ratings are intended as a guideline to help you compare products, rather than a guarantee of warmth.
    View all Sea to Summit Men's Sleeping Bags
  • Technical Specs

    Best Use


    Tested Lower Limit

    28 degrees (F) - EN

    Tested Comfort

    38 degrees (F) - EN

    Temperature Rating (F)

    28 degrees (F)

    Temperature Rating (C)

    -2 degrees (C)


    Regular: 1 lb. 2 oz.

    Long: 1 lb. 4 oz.


    10-denier nylon

    Zipper Location


    Insulation Type


    Water-Resistant Down



    850+ UltraDry Down

    Fill Weight

    Regular: 11 ounces

    Long: 12 ounces


    7-denier nylon

    Sleeping Bag Shape


    Fits Up To (in.)

    Regular: 72 inches

    Long: 76 inches

    Shoulder Girth (in.)

    Regular: 59 inches

    Long: 62 inches

    Hip Girth (in.)

    Regular: 51 inches

    Long: 54 inches

    Stuff Sack Size


    Stuff Sack Volume


    Compressed Volume





    Down certified to the Responsible Down Standard (RDS)

  • Reviews
    117 reviews with an average rating of 4.6 out of 5 stars

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