NEMO Sonic -20 Sleeping Bag

$659.95 to $699.95
Color:Goodnight Gray/torch
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Built to be the only bag you need from -20°F to 40°F, the NEMO Sonic -20 sleeping bag is warmer and more fine-tuneable than ever before. Time to start planning some big-mountain adventures.

  • Features

    • Updated Thermo-Gills™ feature a multi-stage zipper system that increases the bag's usable temperature range and allows you to fine-tune your comfort while inside it
    • Chevron baffle construction better compartmentalizes down, eliminating migration and keeping the down evenly lofted
    • Upgrades include a redesigned profile and draft collar, plus bolstered draft tubes; offset zipper creates a thermally efficient seal
    • Shell and liner fabrics are fully recycled to the Global Recycled Standard (GRS)
    • Shell and liner materials are bluesign® approved
    • 800-fill-power, PFC-free hydrophobic down retains warmth in extra-cold conditions
    • Down is certified to the Responsible Down Standard (RDS)
    • Toester™ footbox keeps feet warmer, provides a waterproof barrier against tent wall condensation and protects down from moisture while drying damp clothes inside the footbox
    • Stretch construction at the knees allows for comfortable side sleeping
    • Covered by the NEMO Lifetime Warranty


    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 NEMO Men's Sleeping Bags
  • Technical Specs

    Best Use



    Tested Lower Limit

    -20 degrees (F) - ISO

    Tested Comfort

    Unavailable degrees (F) - ISO

    Temperature Rating (F)

    -20 degrees (F)

    Temperature Rating (C)

    -29 degrees (C)


    Regular - Left Zip: 3 lbs. 14 oz.

    Long - Left Zip: 4 lbs. 3 oz.


    Recycled nylon

    Zipper Location


    Insulation Type


    Water-Resistant Down



    800-fill-power down

    Fill Weight

    Regular - Left Zip: 2 lbs. 5 oz.

    Long - Left Zip: 2 lbs. 8 oz.


    Recycled polyester

    Sleeping Bag Shape


    Fits Up To (in.)

    Regular - Left Zip: 72

    Long - Left Zip: 78

    Shoulder Girth (in.)

    63 inches

    Hip Girth (in.)

    58 inches

    Stuff Sack Size

    Regular - Left Zip: 10.5 x 14.5 inches

    Long - Left Zip: 10.5 x 15.5 inches

    Stuff Sack Volume

    Regular - Left Zip: 21.2 liters

    Long - Left Zip: 22.3 liters

    Compressed Volume

    Regular - Left Zip: 12.5 liters

    Long - Left Zip: 13.4 liters




    Product meets the bluesign® criteria

  • Reviews
    2 reviews with an average rating of 5.0 out of 5 stars

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