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  • With a European Norm (EN) lower-limit rating of 18°F, the Plasma 15 sleeping bag is suitable for 3-season use and occasional winter outings
  • Filled with certified, super-lofty, ultralight, 875-fill-power goose down (the largest down cluster with the lowest trace of feather) for an unsurpassed warmth-to weight ratio
  • Down is treated to resist moisture to maintain warmth; treated down stays drier 10 times longer, maintains 150% more loft and dries 30% faster than untreated down
  • Pertex® Quantum nylon ripstop shell is lightweight, durable and silky soft
  • Shell is treated with a Durable Water Repellent finish that causes moisture to bead up and roll off
  • Hood drawcord and insulated collar envelop your head and shoulders in warmth; down gasket face muff lets you cinch the hood snug without it digging into your face
  • Vertical baffles prevent cold spots by keeping the goose down fully lofted and in place
  • Down-insulated draft tube backs the two-way, full-length zipper to keep the cold out
  • Wrap-around footbox construction reduces down compression; Flow design with the classic trapezoidal foot box shape lets feet move freely and keeps down lofted for warmth
  • Zipper guard runs the entire length of the draft tube to prevent fabric from getting caught in zipper
  • Marmot Plasma 15 Sleeping Bag features an ultralight stuff sack and storage bag


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

REI membership


Best Use Backpacking
EN Lower Limit 18 degrees Fahrenheit
EN Comfort 29 degrees Fahrenheit
Temperature Rating (F) 15 degrees Fahrenheit
Temperature Rating (C) -9 degrees Celsius
Long Left
2 lbs. 2 oz.
Regular Left
1 lbs. 15 oz.
Ultralight Yes
Shell Nylon
Zipper Location Left
Insulation Type Down
Water-Resistant Down Yes
Fill 875-fill goose down
Fill Weight
Long Left
1 lb. 3 oz. ounces
Regular Left
1 lb. 2 oz. ounces
Lining Nylon
Sleeping Bag Shape Mummy
Fits Up To (in.)
Long Left
78 inches
Regular Left
72 inches
Shoulder Girth (in.)
Long Left
62 inches
Regular Left
60 inches
Hip Girth (in.)
Long Left
60 inches
Regular Left
58 inches
Stuff Sack Size 7.5 x 15 inches
Stuff Sack Volume 11 liters
Compressed Volume
Long Left
7 liters
Regular Left
6.5 liters
Gender Unisex
Rated 5 out of 5 by from my favourite kit Bought about 4 years ago as a treat this is my best bit of kit, one sleeping bag for all UK conditions (at a push!). Sadly no longer available in the UK. Minus 8 certainly is the comfort LIMIT - I wear plenty of clothes to be snug at that temperature, but Mountain Man's 1* review is unacceptable - unless he compared it rigorously against similarly rated bags. I've slept without a tent and woken up snug completely covered in frost. Most of the time I just use it as a duvet, it's that good. The flowgate is meaningless - I can't find any sign of it, but it's not needed anyway. A little longer would be nice if you like to snuggle down into the bag - consider getting the long the long if you are 1.8m+ (i.e. 5'10").
Date published: 2017-01-13
Rated 2 out of 5 by from Brrr I bought this bag for the Colorado Trail last summer and no matter which way I slept, I could not stay warm, even though I'm normally a warm sleeper. The baffles are vertical and enabled the down to shift terribly. I had a Big Agnes QCore SL sleeping pad (which was very comfortable) and the temps really never dropped below 30. I finally had to return it and now searching for another "perfect bag" from specs. I thought this one was the answer to ultra-light, ultra-warm, but I guess not. In its favor, the water repellent was awesome, zipper and collar very nice.
Date published: 2015-04-08
Rated 1 out of 5 by from We Wanted to Love This Bag We were looking to fill a gap between our winter bags(Marmot Couloir, 5 degree & REI, womans Sub Kilo Plus, 0 degree) and summer bags (Mt. Hardware; Phantom 32’s. A late fall-early spring bag, the Marmot Plasma 15 looked like it would fit the bill. So we bought two, regular length. Out the storage bag it looked great, but then it better for a $$$$ sleeping bag. An outdoor magazine gave it great praise. The workmanship was what we expected from Marmot and the black shiny shell with dark blue lining was very tasteful. The 900 fill goose down(2013 spec), very exotic. The claimed weight of 1 lb 15 oz was a big deciding factor for us… we like to keep our pack weights between 20 and 25 pounds and for cycle touring we like to go as light as possible. Here is the reality for us: The bags both weighed in at 2 lbs 1 oz. Not a big deal, I understand claimed gear weight varies and the attractiveness of the bag made the 2 oz difference acceptable. One bag was roomier above the foot box. Substantially bigger and was more comfortable for me (5’ 7” and 185 lbs at that time), and it became my bag. The other bag was a bit tight but my wife (5’ 1” and 104 lbs), it fit her very well. The first backpacking trip, mid-September, Neo-air 47” sleeping pads, Fly Creek UL2 tent… nights were in high 30’s. We like to sleep in our bags with very little on. We found the contact with our bare skin to be clammy and sticky feeling. That and the coolness around our foott area made for an uncomfortable night of sleep for both of us. Even with the clothes we were going to wear the next day in the foot box of the bag… our feet were cool. We wore light weight capilene the next night… took care of the clammy, sticky feeling… feet still felt cool. We decide it was because of the length of our pads. Second use… late September, backpacking, with Big Agnes Q-core SL 72” length sleeping pads & Fly Creek UL3… nights were in the mid to low 30’s. Winds and heavy mist at night. We wore capliene to take care of the clammy and sticky thing. We were very surprised… we were both cold. The moist air, wind and 30 degree temperatures made for very chilly nights. We thought that the roominess of the 3 person tent and wind did not allow for warming the tent enterior with our body heat as well as in a smaller tent. I was thinking about returning the bags to REI after this trip. Third use… I did a solo cycle tour, late fall Exped 9 down sleeping pad and Fly Creek UL2 tent. Again, I wore capilene… I was getting use to wearing it with these bags… and socks. Now, I am a warm sleeper. By myself, in a two person tent without my wife… I slept a bit cool at night… I was very unhappy. I was thinking about the number of nights I have had cool to cold nights in my Phantom 32… we have had them for years… for backpacking, paddling and cycle trips. There has been very few cool or cold times. We have a great relationship with our local REI… they said for us to return them, we said we would try again to see what happens, because we really wanted to LOVE THESE BAGS! Last trip with this bag for me… Cycle Touring, early May, Big Agnes Q-core SL 72” sleeping pad, Fly Creek UL2 tent… nights were in the mid to low 30’s. We wore our capliene. We wore thick socks. We put the following day’s clothing in foot area of the bag to keep warm and for added warmth. During the night I put on my down shirt over my capliene and my wife put on her lightweight down jacket. We got cold! We are experience outdoor people… we snow camp; backpack, cycle tour , canoe, sea kayak and raft. We own and use three other sleep systems for our various outdoor activities and are very pleased with them. We are totally baffled with the unsuccessful sleeping experience with these bags. I returned mine today. My wife is still hanging on to hers. I think she will be returning it soon… she sleeps colder than me. She likes how the bag fits her and I on other hand found it tolerable… even now at 170 lbs. Would I recommend it to a friend? I love Marmot gear... I guess I would say yes if you bought it from REI... but I am going to mark "NO".
Date published: 2014-05-15
Rated 5 out of 5 by from Awesome product! This sleeping bag is without any doubt the best purchase I've made in terms of camping! Super lightweight, confortable and warm.. You won't regret with this item!
Date published: 2015-07-17
Rated 5 out of 5 by from 3-season blast furnace I've had this bag for 4 years now and it, like most Marmot products, is holding up great! I have to write this review to balance the reviews stating this bag is too cold. I can't disagree more. I have used this bag without a tent down to the mid 20's with ultralight thermals and it was perfect. When the lows rise to the low 30's I have to switch bags...this bag is too warm! I am 6'2" 185# and bought the long bag and it fits great. With the bag fully zipped I can still remove my thermal tops and bottoms and/or socks. Well sized for me. FWIW, this bag also launders well. I just washed it his week according to Curly's instructions and it came out great. Next time I will add more tennis balls(used 3) and start earlier in the day. It took 6 hours to fully dry on low.
Date published: 2016-04-24
Rated 4 out of 5 by from Works for me I used this in a Hennessy hammock with a Hammockgear Incubator 20 degree down underquilt a couple weeks ago when the temp dropped to 12 degrees and i was pretty warm. Granted I was wearing Goosefeet down socks and a Rab Microlight down jacket. Pretty satisfied with it. It was a gift but if I was shopping for a new bag I wouldnt pick this mainly due to the price. I would probably go with a western mountaineering.
Date published: 2014-12-12
Rated 4 out of 5 by from Light, Warm, Comfortable... Expensive I purchased this sleeping bag close to a year ago and have used it on a number of backpacking trips. I am 6' 3" 210 lb. and sleep on an Exped Synmat UL 7 in as little clothing as possible. During two of these trips the temperature dropped below 30 (I always carry a thermometer that captures the 24 hour high and low) and I stayed very warm. However, I will mention that it seems to get cold spots easily if compressed (which really is a characteristic of down in general), for example if your feet are pressing up against the side of the tent or if your butt is resting on the ground from an under-inflated pad then you will feel the cold. It is also a roomy bag which can be good and bad... too big and it gets cold easy too small and you cant move; this bag does a good job at being big without being cold. Lastly, my other minor complaints include that the zippers can catch the fabric if your not careful and that I wish the storage bag was a solid cloth as opposed to a mesh bag. All in all it's a roomy, warm bag, that's light, and packs small but costs about $100 too much.
Date published: 2015-02-06
Rated 5 out of 5 by from I Love This Sleeping Bag The one I have is labeled "900" fill. I am so glad that I bought this bag. I hope it lasts a long time. The trick to staying warm is that you need to sleep naked -- I have never been cold sleeping naked down to about 18F (measured with a thermometer). I am very slim (6' 5", 160 lb), so I get cold very easily. Every time I have felt a little cool I just remove everything I'm wearing and I warm right up. I especially like the fact that the long size of the bag is longer than any bag I've previously owned. I'm about 2 meters tall, so that is important. I also like the way that the cords and snaps are setup in around the head of the bag. It is very easy to pull the collar tight to keep out drafts and the two different draw strings feel different in the dark, so you can tell them apart. The feel of the inside material is sort of silky smooth. This bothered me at first, but now I'm used to it. I love how light weight the bag is and how small it can be packed. I'm into "minimalist" adventure touring on smaller motorcycles, so the fact that it can be packed into a 6" diameter by 12" long dry bag makes it much easier to strap on the bike.
Date published: 2016-12-18
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