$109.95 to $119.95
Color:Castle Rock/smoke
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An outdoor superstar, the Kelty Cosmo 40 down sleeping bag features cozy 550-fill-power duck down and a buttery-soft nylon shell that'll have you daydreaming about more quality time under the stars.

  • Features

    • 20-denier nylon shell fabric is durable and soft; C0- and PFC-free durable water repellent (DWR) finish sheds moisture and stains
    • 550-fill-power duck down is lightweight and warm; quilt-through construction keeps insulation in place
    • Handy stash pocket gives you a spot to keep your headlamp, cellphone or other small essentials close by
    • Dual-slider locking zippers allow for easy ventilation
    • Zipper draft tube with antisnag design makes it easy to get in and out of the bag
    • Natural-fit spacious footbox gives you more room to wiggle your toes
    • Stuff sack included


    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 hat, 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 Kelty Men's Sleeping Bags
  • Technical Specs

    Best Use


    Tested Lower Limit

    40 degrees (F) - ISO

    Tested Comfort

    48 degrees (F) - ISO

    Temperature Rating (F)

    40 degrees (F)

    Temperature Rating (C)

    4 degrees (C)


    Long - Right Zip: 1 lb. 14.4 oz.

    Regular - Right Zip: 1 lb. 11.2 oz.


    20-denier 400T nylon

    Zipper Location


    Insulation Type


    Water-Resistant Down



    550-fill-power duck down

    Fill Weight

    Long - Right Zip: 10 ounces

    Regular - Right Zip: 9.1 ounces


    50-denier 300T polyester

    Sleeping Bag Shape


    Fits Up To (in.)

    Long - Right Zip: 84 inches

    Regular - Right Zip: 78 inches

    Shoulder Girth (in.)

    Long - Right Zip: 64 inches

    Regular - Right Zip: 62 inches

    Hip Girth (in.)

    Long - Right Zip: 60 inches

    Regular - Right Zip: 58 inches

    Stuff Sack Size

    Long - Right Zip: 7 x 11 inches

    Regular - Right Zip: 7 x 10 inches

    Stuff Sack Volume

    Long - Right Zip: 6.9 liters

    Regular - Right Zip: 6.3 liters



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