Sea to Summit Amplitude Down 5F Sleeping Bag

$479.00 to $499.00
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Ideal for trips where you return to the same campsite each evening, the Sea to Summit Amplitude Down 5F sleeping bag brings spaciousness, cozy down and versatile ventilation to your sleep setup.

  • Features

    • Each side of the Amplitude has a full-length side zipper; a third zipper can be found in the foot box, allowing the top section to be removed and used as a comforter
    • Shaped hood and zipper draft tubes keep cold out and warmth in
    • 750-fill-power duck down provides cozy warmth
    • Vertical baffles over the chest prevent down shifting as you roll over in your sleep
    • Includes lightweight Ultra-Sil™ compression bag for easy storage and transport
    • Form a snug sleeping bag for 2 by zipping to another Amplitude or Explore, Ascent™, Trek™, Traverse™, Altitude™, Journey™ or Venture™ sleeping bag (not 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 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

    5 degrees (F) - EN

    Tested Comfort

    21 degrees (F) - EN

    Temperature Rating (F)

    5 degrees (F)

    Temperature Rating (C)

    -15 degrees (C)


    Regular: 3 lbs. 1 oz.

    Long: 3 lbs. 8 oz.



    Zipper Location


    Insulation Type


    Water-Resistant Down



    750-fill-power duck down

    Fill Weight

    Regular: 1 lb. 11.2 oz.

    Long: 1 lb. 14.4 oz.


    20-denier nylon

    Sleeping Bag Shape


    Fits Up To (in.)

    Regular: 72 inches

    Long: 78 inches

    Shoulder Girth (in.)

    Regular: 76 inches

    Long: 82 inches

    Hip Girth (in.)

    Regular: 75 inches

    Long: 80 inches

    Stuff Sack Size

    8 x 18 inches

    Stuff Sack Volume

    14 liters

    Compressed Volume

    Regular: 10.4 liters

    Long: 12.3 liters



  • Reviews
    7 reviews with an average rating of 4.3 out of 5 stars

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