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  • Ultralight Pertex Microlight 20d nylon ripstop with durable water repellant finish is resilient to wear
  • Certified 800-fill goose down with Down Defender treatment for improved water-resistance in wet conditions
  • Fold-down second zipper provides added ventilation and easy bag access
  • Nautilus multi-baffle hood envelopes your head in warmth; adjustable drawcord cinches hood about your face
  • Anatomically designed footbox with wrap-around construction allows down to loft fully around your feet for optimum warmth and comfort
  • Smooth, curved baffles reduce down shifting; stretch tricot baffles provide strength and durability for long bag life
  • Insulated draft tube backs a full-length, 2-way, snag-free zipper to prevent cold air getting in
  • Internal stash pocket stows nighttime essentials
  • Zipper garage keeps zipper pull in its place at night
  • 2 hang loops for storing and airing out sleeping bag
  • Stuff sack and storage sack included


Many sleeping bags are rated for temperature by an independent testing protocol, the European Norm (EN) 13537. Each bag gets two ratings: a Comfort rating and Lower Limit rating. The Comfort rating is the lowest temperature at which the bag will keep the average woman (or "cold sleeper") comfortable, and the Lower Limit rating is the lowest temperature at which the bag will keep an average man (or "warm sleeper") comfortable. Everyone's body and sleep comfort is different, so EN Ratings are merely a guideline to help you compare products.

View all Marmot Men's Sleeping Bags

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Best Use Backpacking
EN Lower Limit 13.5 degrees Fahrenheit
EN Comfort 25.2 degrees Fahrenheit
Temperature Rating (F) 15 degrees Fahrenheit
Temperature Rating (C) -9 degrees Celsius
Long Left
2 lbs. 4.5 oz.
Regular Left
2 lbs. 1 oz.
Shell Nylon
Zipper Location Left/Right
Insulation Type Down
Water-Resistant Down Yes
Fill 800-fill goose down
Fill Weight
Long Left
22 ounces
Regular Left
19.8 ounces
Lining Nylon
Sleeping Bag Shape Mummy
Fits Up To (in.)
Long Left
78 inches
Regular Left
72 inches
Shoulder Girth (in.)
Long Left
63 inches
Regular Left
61 inches
Hip Girth (in.)
Long Left
58 inches
Regular Left
56 inches
Stuff Sack Size 7 x 14 inches
Stuff Sack Volume 8.8 liters
Gender Unisex
Rated 5 out of 5 by from Great bag! I took this bag on my 2016 Appalachian Trail thru-hike and with a silk liner I stayed warm in March / April throughout the Smokies. Great bag. Just zip it up and down carefully or you will snag the material and tear it.
Date published: 2016-09-10
Rated 5 out of 5 by from Perfect Used on Shasta in May -- Was perfect for 20-30 degree weather -- very warm, very light, and good price point in this category.
Date published: 2016-06-21
Rated 5 out of 5 by from So nice I bought a backup I've had a Helium for a year or more and just love the soft silky feel, plus it does a great job of keeping me warm. When it hits about 20 I need to put a blanket or something on top, but I sleep really cold, so I think a normal person would be comfy at a lower temp. I love this thing so much I was awake one night thinking about what I would do if I wore the darn thing out (not likely, I have Marmot bags from the 1990s that still work fine), so I decided to buy a second one for a backup. Some people like having extra jugs of water and cans of food in their basement for emergencies, but with a second Helium, I think I can weather about anything now, and I sleep like a baby. This is the most comfy and luxurious feeling bag I've ever owned, and I'm a sleeping bag junky. I have several Marmots (including a newish Hydrogen and Trestles, along with an old Raging Inferno), several North Face, and a couple of more generic brands, not to mention the ones I've given away. Some women buy shoes, I buy sleeping bags. I love this bag.
Date published: 2017-06-03
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Does this come with a compression sack? If not can I use a compression sack to compress this sleeping bag further?

Asked by: Sasakthi
The Helium Down Sleeping Bag comes with a regular stuff sack and a storage bag. You can certainly use a compression stuff sack from the selection linked below. A 10 liter size bag is appropriate.
Answered by: REIservice
Date published: 2017-02-20

Does the zipper go around the foot box or just half way down on either side?

Asked by: hubba bubba
​The main zipper goes down to about one foot from the bottom.
Answered by: REIservice
Date published: 2017-03-31
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