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Pro alpinist Fabrizio Zangrilli uses the ultralight Marmot Helium MemBrain 15-Degree Sleeping Bag to stay warm and dry at the top of the world, so odds are that this down sleeping bag will work for you, too. Marmot’s waterproof breathable MemBrain construction repels snow and water while expelling perspiration so you can take full advantage of the toasty down insulation without worrying about it clumping and leaving you high and wet.

  • EN comfort rated at 25.5 degrees F for cozy three-season use; lower limit rated at 14 degrees F for occasional use during winter outings
  • MemBrain 2L waterproof fabric helps shelter the down insulation from external condensation, snow, and water
  • MemBrain 2L fabric is also highly breathable so evaporating sweat won't condense inside the bag and cause the down insulation to clump
  • Lightweight 850-fill goose down insulation offers a superior warmth-to-weight ratio and rebounds well after repeated compressions
  • Nautilus 6-baffle hood with down-filled collar and drawcord guards your face in drafty tents
  • Stretch tricot baffles extend the life and maintain the shape of the bag and improve warmth retention
  • Face Muff allows hood to be cinched without irritating your face
  • Large trapezoidal footbox decreases constriction at the bottom of the bag
  • Nylon stuff sack and cloth storage bag included
  • Reviews
  • Q & A

What do you think about this product?

Have questions about this product?

The Best Bag I Ever Used

  • Familiarity: I've put it through the wringer

I took This bag for 1 year of backpacking all over South America, and this bag perform beyond me expectation.
Even in the far south, at the end of south america, when everything around and on top of my tent was frozen and coverd with snow, I was cozy and worm inside the bag.
I was never too cold, and the weather was never a problem for me.
It's super light, so you don't really feel it in your backpack, and it can be compressed to a very small pack.
This bag passed my test BIG TIME!!!
You'll love it!

Awesome Bag

  • Familiarity: I've put it through the wringer

Used this bag Elk Hunting at 12,000ft on some cold nights...below 15 degrees. I was warm in shorts and t-shirt. Loft is awesome, and packs small. Also used it on warmer nights, and just slept with the zip halfway down. No complaints at all. Great product.

No complaints.

  • Familiarity: I've put it through the wringer

When a sleeping bag is giving you no complaints, you know it's doing its job. I've used the bag in a tent for circa 25 nights, of which 5 snowed and 5 rained. Although the bag was not directly exposed to the elements, it was exposed to plenty of condensation and moisture. Compared to my husband's non-membrain, non-Marmot, ripstop covered bag that was exposed to the same conditions, the Membrain's water repellency performed stunningly! I'm a cold sleeper, and down to freezing temps, including a night in the snow at 15,000 ft, I had no problems. I've yet to test it in 15F degree temps and anticipate that for a woman, I'd need to layer more clothing inside the bag. Also, the outer shell dries really fast, faster than rip-stop.

it will save your life....

  • Familiarity: I've put it through the wringer

.... like when its really cold and you decide to go out on a winter splitboard trip and then a blizzard rolls in a day and half early, and your tents getting blow apart and you think your gonna die cuz theres 70+ mph gust of wind and youre rocking your 3 season tent...... but you'll stay warm damn it!

Best bag on market

  • Familiarity: I've used it once or twice and have initial impressions

I love this bag, I used my friends during a backpacknig trip. I like to sleep in a hammock when I camp. It gets pretty chilly in the Wasatch so having a bag that keeps you as warm as this is perfect. I've slept in this bag in sub 20 degree weather and I was toasty with only underlayers on. Compresses great and super light to carry around. Highly recommend this bag.

It Actually Keeps Me Warm!

  • Familiarity: I've used it several times

I tend to freeze at night no matter how many layers I am wearing. I got this bag and I had to unzip it to keep from sweating! It compresses really well too. I absolutely love it.

light and warm

  • Familiarity: I've used it several times

Just got back from an elk hunt in Colorado. We spiked camp back in a few miles. The bag was lighter than my buddies and I was toasty warm all night in just my skivvies. He on the other hand had his insulated under clothes, regular clothes, and coat on and was still cold. I even zipped my bag down a little as it was only in lower 20's. Best sleeping bag I've ever owned.

Favorite bag I've ever owned.

    Marmot has a terrific product here, I usually go to Marmot for all of my down products, and this was no exception. It's extremely light weight, compresses down into the stuff sack very easily, and could be compressed more if you wanted to buy a compression sack for it. Has definitely kept me warm in 0-10 degree situations with minimal or no layers on. I haven't had to test the waterproofing of the MemBrain technology as I keep my down products extremely dry all costs, but I have faith in it. I have had some heavy dew on mornings when I've slept out of a tent, and there was no issue with the bag.

    I really have nothing negative to say about this bag, and will continue to use Marmot almost exclusively for my down products.

    Worth the Price

      Incredibly small and light for its rating. Had it out in 20 degrees and was hot wearing thermals. The bag has seen some water, it shed it with no problems to date. Fits well around me without feeling claustrophobic, I'm 5'9, 140. This bag is amazing for cold weather but be prepared to get a warmer bag for summer.

      my go to sleeping bag

        For the majority of situations this bag works perfectly. The fill makes it comfortable in all but the coldest winter weather and the shell sheds condensation like no other bag in its class. It's not fully waterproof and that is a good thing because fully waterproof bags are much heavier and when the only water you are trying to shed is condensation it works perfectly. I used to have the non EQ helium and the shell was much thinner and condensation would ruin the loft on long treks. The EQ version fixes both of these problems and is all around a more sturdy feeling bag. Definitely worth the extra cash over the original.

        Warm at -10 F

          Clear Michigan January sky, stars bright as headlights, 15 mph wind, -10 F.
          Slept on a tarp, z-pad, a thermarest and with a poly bag liner. Warm and cozy!
          Of course I had all my clothes on, two hats and a light pair of wool liner gloves. But I still pushed this bag 25 degrees!
          If I slept in my MH EV-3, I probably would still get a great night's sleep at -20 degrees.
          Don't think about the cold money, think about a warm sleep. Sweet dreams!


            I haven't had the opportunity to try this out in the cold yet but I am a big guy, 270 pounds and I have plenty of room in this bag. Just trying it out in the house, I was sweating after only a minute in the bag. Can't wait to get out there and try it in the cold.

            Light, Warm, Dry, Packable

              Took this bag into heavy snow and outside temps below 10 degrees. Inside tent the temps were slightly higher. Bag worked well, it was cold, snowing and damp all week, with over 10 inches of snow accumulating on the already 6 inches. Bag worked well. The weight and packability combined with the 15 degree rating and Membrain were the draw. I'm 5'10" and 190 lbs. it's just slightly snug in the shoulders, but hey, its camping.


              • Familiarity: I've used it once or twice and have initial impressions

              Got this bag a few weeks ago and decided to try out it's warmth by camping out in the back yard on a 25�F night. This bag is very light and would be great for backpacking. However, I found the draft flap to be inadequate. I don't know if it's drafty due to it's lightweight design or if the bag I received just had a flaw, but I had a hard time getting the flap to stay put. I also found the drawstring on the hood to be difficult to cinch down. Both of these items made it difficult to take full advantage of the 850-loft down, so given the price of this bag I decided to return it and go with the Marmot Pinnacle instead.

              I see many reviews that say this bag is...

              I see many reviews that say this bag is great for colder temperatures, but how does it transition into warmer weather?

              Best Answer

              Hi Megan,

              I'm able to use my 15 degree bag throughout the whole year. I adjust the heat by unzipping it when it's warmer out. In the middle of the summer, if I'm going to be in a pretty hot area, I'll take an older much less warm bag.

              Hello. I want to purchase this bag but...

              Hello. I want to purchase this bag but can't decide on length. I am 5'11.5" and will use this bag for 3 season use. Regular or long?!?!?!?! Thanks.

              Is this bag available in right zip? My...

              Is this bag available in right zip? My girlfriend has this bag in a left zip and I want to be able to zip them together. If so when will you have them in stock or is this a custom order type deal?

              Does the membrane version of this bag have...

              Does the membrane version of this bag have an internal dew point? I have a similar mountain hardwear bag, that I feel damp and clammy in.

              i have a hard time believing that this bag...

              i have a hard time believing that this bag packs down to 7x7"
              if it does i would buy it, but 7x7 and 7x15 is a huge difference.
              are you sure its not a typo? it is misleading and should be taken care of if so.

              I have not checked this one out but down bags can pack very small. My Lafuma bag that is the same temp fits in a stuff sack that I can squeeze down to a smaller size than 7x7 so if anything I would guess it takes up less space than 7x7inches.

              Best Answer

              I was curious about your question so I tried it myself. I packed the Helium into a Granite Gear size XS compression sack and cranked it down to 8" tall and 6.5" across. Pretty small, as you can see from the photo that compares the compressed bag to a Nalgene. Hope this helps!

              I was curious about your question so I tried it myself.  I packed the Helium into a Granite Gear size XS compression sack and cranked it down to 8" tall and 6.5" across.  Pretty small, as you can see from the photo that compares the compressed bag to a Nalgene.  Hope this helps!

              I am trying to decide between this bag &...

              I am trying to decide between this bag & the new RAB Neutrino 400 or 600 bags (I have just purchased, but not yet used, a RAB Neutrino Endurance downie & it looks excellent). The Marmot by dimension seems to be a lot roomier, a comment some have made regarding this bag; not sure if I think this is a good thing as it equates to more air flow, particularly with no draft collar & probably meaning a colder bag? The RAB's seem to be a lot slimmer cut (truer mummy shape) & hence are probably more efficient? Can someone comment on this please? Also, how would people rate the outer fabrics of the 2 bags, the Membrain sounds like it is near waterproof yet the RAB's Pertex Endurance is pretty close to waterproof. As there are no reviews on these RAB bags yet any commenst / descriptions would be very useful in helping me decide. Thanks :-)

              Why is this bag so light? Where is different...

              Why is this bag so light?
              Where is different from "Helium(not EQ)" in this?

              Is this the old EQ or the new Membrane? ...

              Is this the old EQ or the new Membrane? Is the zipper the same as on the Pinnacle? Also, is there a bottom-up zipper (can't tell from the photo).