CWM Sleeping Bag: -40F Down
Style & Size:
Quantity
Why We Like The CWM Sleeping Bag
We like to get some shut-eye in the death zone with a little help from the Marmot CWM -40 Degree Down Sleeping Bag. This 800-fill goose-down-insulated bag is built for the coldest, harshest weather on the planet, from the South Col to the South Pole. Its waterproof, breathable Pertex Shield 2L laminate prevents rogue bits of water, tent condensation, and melted snow from clumping your down and ruining your sleep (and chances of summiting tomorrow). The outer fabric itself is made from rugged 30D nylon ripstop and the lining from 30D nylon ripstop Pertex Microlight, which has a soft feel and the durability to prevent feather leaks.
Details
- One of Marmot's warmest sleeping bags built for mountaineering
- Waterproof, breathable Pertex Shield 2L maximizes weather protection
- 800-fill down insulation has a temperature rating of -40F
- Cross-baffle construction and draft tubes prevent cold spots
- Adjustable hood cinches tight for the coldest nights
- Storage and stuff sacks included
- Item #MARZ9N1
- Material
- [membrane/laminate] Pertex Shield (2-layer), [face fabric] 30D nylon, [lining] Pertex Microlight (30D nylon)
- Insulation
- 800+-fill Power Goose down
- Shape
- mummy
- Zipper
- left, right
- Max User Height
- [regular] 72in, [long] 78in
- Shoulder Circumference
- [regular] 63in, [long] 65in
- Hip Circumference
- [regular] 61in, [long] 63in
- Foot Circumference
- [regular] 44in, [long] 46in
- Bag Length
- [regular] 83.5in, [long] 89in
- Draft Tube
- yes
- Pockets
- none
- Pad Retainer
- no
- Fill Weight
- [regular] 47oz, [long] 50oz
- Degree
- -40F
- Storage Sack
- mesh
- Stuff Sack
- nylon
- Stuff Size
- 9.5 x 19in
- Claimed Weight
- [regular] 4lb 15.5oz, [long] 5lb 4.5oz
- Activity
- winter camping, weekend camping
- Manufacturer Warranty
- lifetime
Reviews
Q&A
What do you think about this product?
Overall Rating
5 based on 12 ratings
Review Summary
Fits Small
Screen reader users: the following list provides a visual scale to illustrate the product fit. Please refer to the heading above for the fit type in text.View
Selecting an option will reload the available reviews on the pageJanuary 16, 2025
Excellent Bag in Arctic Ascents!
[This review was collected as part of a promotion.] Outstanding ECW bag that enables great warmth and survivability in extreme cold bivouac and alpine camps. Highly recommended for its cube design, middle zip and pockets to protect, and secure key items that require accessibility from the bag.
Originally reviewed on marmot.com
June 19, 2024
Missing stuff sack
The bag arrived, and looks great but was missing a stuff sack. Bag also has that weird 'stale' smell like it's been used but had all the tags on it still. I tried the online click-to-chat (no response) and the 800 call center number which put me in touch with someone (sounded Indian) who could not understand me and refused to transfer my call. Super disappointing experience
January 22, 2024
Nice bag, long enough, on sale, good deal
[This review was collected as part of a promotion.] Nice bag, long enough, on sale, good deal, bought two of them, zipper doesn't get stuck, recommended
Originally reviewed on marmot.com
January 14, 2024
Ridiculously warm
Finally got a chance to field test the bag in zero degree conditions. Once inside, I never noticed the chill. I even shedded a layer half way through the night. The col is by far the warmest sleeping bag I've ever tested.
Originally reviewed on marmot.com
December 16, 2023
Just do it
WARM! Big, but definitely warm. Love that the zipper is in the center. Also love the pockets inside the sleeping bag.
Originally reviewed on marmot.com
October 6, 2023
Really nice bag; runs small
- Size Bought:
- regular
- Height:
- 5' 11"
- Weight:
- 163
It's warm; I like the central zipper. Some folks have written reviews saying the zipper is hard to use -- maybe they updated it? Quite the large/easy zipper to me. And small zippers drive me nuts! I'm writing this to note that as someone 5'11, I don't think I'm a regular, even at that is rated to 6 feet. My toes touch the bottom pretty firmly. If I were say 5' 9, I'd be quite happy. And this is me in the bag in my pajamas, not some climbing snowsuit. I'm surprised this is the case....
July 8, 2023
Dream Level Comfort
[This review was collected as part of a promotion.] I have a collection of sleeping bags that I have acquired over many years of backcountry travel and recreation. All are down, and all come from reputable, high-end outdoor companies. They are all nice in their own regard, but I can honestly say that none come close to this beautiful sleeping bag. From the superb warmth of the mega-stuffed down filling, to the cleaver zipper layout, this bag delivers dream level comfort. I have yet to test it to it's -40 degree rating, but it has over performed snow camping and skiing the Eastern Sierra's. Not a hard choice picking this bag, however, I did dither between the -40 degree and the -20 degree option. It would have been plenty warm and I like the yellow color, but I figured, "go big", after all I am the Original Marmot Man.
Originally reviewed on marmot.com
December 26, 2022
Like being in Heaven. You won’t regret buying this
[This review was collected as part of a promotion.] I FINALLY HAVE ONE! I’ve wanted a Marmot bag for over 30 years and it’s worth every penny. Marmot has used their years of experience perfecting this sleeping bag. I love the features and boot bag and extra foot room. I am 6 foot and got the 6’6” bag- zippers don’t snag with their technology. Side zips are great. You will love this bag. I used mine with double groundsheets and recommend 1 for insulation - while I was not in a tent.
Originally reviewed on marmot.com
December 14, 2022
Absolutely worth it!
I was hesitant to buy with the price tag but I live out in the middle of nowhere oregon up in the mountains at 5000ft and go to around 8000 all the time for winter camping, this thing had been amazing!
Originally reviewed on marmot.com
December 14, 2022
800 fill sleeping bag
[This review was collected as part of a promotion.] Best...warmest bag I have ever used!! Never cold!!!
Originally reviewed on marmot.com
Do you have a question about this product?
March 15, 2025
What is the packed size in L?
Originally reviewed on marmot.com
August 27, 2024
How much does it weigh?
Originally reviewed on marmot.com
July 10, 2024
It doesn't appear there is any way to vent the feet, correct? The arm holes and center zip are brilliant and what I need, but a few other competitors offer a foot hole or zipper so you can vent or walk around while wearing the bag.
Originally reviewed on marmot.com
June 6, 2024
Marmot CWM Sleeping Bags, I know it. WHERE MADE IT. MADE US OR ANOTHER COUNTRY.
Originally reviewed on marmot.com
May 14, 2024
Is the bag rated for -40° F or -40° C?
Originally reviewed on marmot.com
February 9, 2024
What does CWM stand for?
Originally reviewed on marmot.com
February 3, 2024
Can the side zips be operated from inside the bag or does the center zip have to be undone to access the side zips?
Originally reviewed on marmot.com
January 8, 2024
How long is this sleeping bag? I am 6’6’’
Originally reviewed on marmot.com
December 2, 2023
What is the purpose of the two interior pockets on the left side with no closures? Do they have a specific application?
Originally reviewed on marmot.com
November 30, 2023
What is the fill weight of this sleeping bag?
Originally reviewed on marmot.com
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