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Western Mountaineering Puma Super MF Sleeping Bag: -25F Down

$865.00 - $925.00

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  • 5ft 6in/Left Zip
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  • 5ft 6in/Right Zip
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  • 6ft 6in/Left Zip
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  • 6ft 6in/Right Zip
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  • Royal Blue - Unavailable

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Stay warm during the most brutally cold nights.

The Western Mountaineering Puma Super MF Sleeping Bag is a solid choice for mountaineers bold enough to take on Old Man Winter at his strongest. Interlocking draft tubes deflect creeping cold and work in conjunction with the nine-inch loft and 36 ounces of 850+ down fill to give the Puma Super MF a monstrously warm -25 degree rating.
  • Highly breathable, water-resistant shell protects the down insulation from frost, condensation, and spindrift
  • Ultra-premium 850-fill down insulation retains your body’s warmth and provides a higher warmth-to-weight ratio than any synthetic-fill insulation
  • Interlocking draft tubes and a down-filled collar prevent energy-sucking drafts from zapping your slumber
  • Wider shoulder girth allows for extra layering in brutally cold environments
  • Western Mountaineering bags are made in the USA
  • Item #WES0037

[shell] MicroLite XP (polyester microfiber), [lining] nylon
850-fill down
DWR treatment
Max User Height
[short] 5 ft 6 in, [regular] 6 ft, [long] 6 ft 6 in
Shoulder Circumference
[short] 62 in, [regular] 64 in, [long] 66 in
Hip Circumference
[short] 55 in, [regular] 56 in, [long] 57 in
Foot Circumference
39 in
Fill Weight
36 oz
-25 F
Storage Sack
Stuff Sack
Stuff Size
[short] 9 x 18 in, [regular, long] 10 x 20 in
Claimed Weight
[short] 3 lb 4 oz, [regular] 3 lb 7 oz, [long] 3 lb 10 oz
Recommended Use
alpine & expedition, winter camping
Manufacturer Warranty
1 year

Tech Specs

What do you think about this product?


>Rating: 5

Good bag

I've used it several times

As with most things, you get what you pay for. WM bags aren't cheap, but when you're at 12,000ft in the middle of winter and the wind is rolling over your tent like a freight train you'll be glad you didn't try and save a few bucks...

>Rating: 5

Awesome winter bag!

I've put it through the wringer

I have used this bag down to -15F, and slept completely warm. I am a cold sleeper, and normally need a bag rated to at least 20 deg more than claimed. but not so with this bag. It really is WARM! I just crawl in, and am immediately toasty no matter how cold it is. But, it weighs less than 3.5 lbs! And stuffs down quite small. The microfiber shell rocks; it sheds water quite well, blocks wind, and breaths very well. Fabulous bag, I wouldn't go winter camping with any other.

>Rating: 5

Best Nights Sleep in the Sierras

I've used it several times

This sleeping bag is simply perfect. It is pretty lightweight and very warm. Western Mountaineering uses the highest quality down so you really stay comfortable and warm all night. After too many cold nights in my normal sleeping bag, I finally made the splurge and have never looked back. I highly recommend to anyone who is camping in cold temperatures! I also loved that it runs in small sizes because the smaller size saves space in my pack and keep my feet warmer.

>Rating: 5

Worth it.

I've used it several times

Now having used for a season, can certainly say this lived up to expectations. Only tested down to around 0, maybe slightly below, but was toasty warm even down to my toes and with minimal base layer on. Would highly recommend, especially for ladies who are always cold like me, for anything below freezing. As far as the price, I see this as an investment and am hoping it will stand the test of time. I think it's pretty reasonable price to pay given (1) it's the same price as a few nights in a nice hotel, and (2) you're getting super comfy night's sleep at 10,000 ft in the winter in the Sierras :). Lastly, packs down to a decent size with some effort, got this into a smaller, older TNF stuff sack so it fits horizontally in my Osprey pack.

>Rating: 5

The capsole of warmth and happieness

I've used it several times

This bag is the real deal. WM is in my opinion one of the best manufacturers of down goods. Nothing fancy, just some of the highest quality of materials simply put together. What else can I say, it's super warm, lightweight for it's size, and very breathable. It's the ultimate winter sleeping bag. Looking around Backcountry a bit for other -25F bags, there is no competition. You can consider buying a Marmot or TNF, but it always feels like there is something missing with them. Western Mountaineering makes a living off of manufacturing the best down garments, where as TNF and Marmot aren't the specialists here. WM is always highly recommended especially when the temp drops.

>Rating: 5


I've put it through the wringer

All I can do is gush about this bag. I've slept in it down to about 0 degrees at 10,000' and it is toasty warm. I've also slept in it at 20 degrees and it is not uncomfortably warm - a little bit of venting was all it took. Don't get me wrong, it's too big, bulky, and warm for a 3 season bag, but if it's going down below freezing it's my go-to bag - even over my WM Alpinlite which is rated to 20 degrees. For a full-on winter bag is is very light and compressible. Nothing but tremendously positive things to say. Is $750 a crazy amount to spend on a sleeping bag? Probably. Do I feel like I got my money's worth? Absolutely. Buy quality gear once, take care of it, and use it for years. The WM Puma certainly fits that mold

>Rating: 5

WM Puma 1st use

Backcountry overnight in Yosemite last week, temps in low teens, elevation 7000ft, bag was toasty warm, material is silky smooth. Im just over 6 ft, 215lbs and the reg bag sized perfectly. Zipper worked smoothly and draft collar functioned well. The loft on this bag is amazing and it compresses well when packed down into the stuff sack.

>Rating: 5

Awesome bag - wrong color, it's actually bright blue!

this bag is super toasty and has enough shoulder circumference for a large individual like me (5'11 240lb 10% body fat) - though I might return this since I can't use a bag that is bright blue, and yes in the pics on the site it is green...

Looks blue to me

>Rating: 5


This is simply the finest bag I've ever slept in. Took it to Denali in late May. Was toasty every night. Nothing finer than slipping into this gem after the end of a long day. Foot box had enough room to keep my boot liners warm on summit day. Shell did a nice job keeping the morning frost on the outside of the bag. For the warmth, one of the lightest bags.

>Rating: 5

first impressions...

I haven't put this bag to the TRUE test yet (sub-zero), but Im certain it will do just fine. Im amazed by the build quality, materials, and construction. The loft is amazing, no joke 9 inches easy! Its expensive, yes, but worth every penny. For me, it was important to have a bag that would allow me to sleep well during the bitter cold winter nights. It's the equivalent of a one night stay at a 5 star hotel, except this bag will bring me more joy than any 5 star hotel ever could, for many years to come.

>Rating: 5

this is the bag

got this for my girlfriend, and winter camping will never be a struggle again. with 9 inches of loft, you feel as if you are hovering when you sleep in this bag. have not taken it down to below 0 yet, but at 0 she said it was her best cold weather night she ever had. this is a well made american product, buy it and never fear the cold again.


WM Puma


I have used this bag down to -15 at the base of Mt Washington in New Hampshire and throughout the White Mountains, and frankly I wouldn't use anything else except Western Mountaineering for winter backpacking. This particular bag has an awesome draft collar and draft tube along the zipper and it lofts incredibly well for those 12+ hour nights in New England winter.

>Rating: 5

Why take more? truth I've never used this bag. I only wish I'd taken it to Denali when I was old enough (young enough) to enjoy it! The "-40" bag I used to climb Denali (one of Earth's coldest environs) was a shadow of this bag. That was 1980 and I didn't know about Western at that time. This bag is astoundingly thick and warm for its 3 lbs. 4 oz. By most accounts, most users of this bag will swear that it's good to -40. Certainly with a tent I would have no question about that. The shell is surprisingly water resistant. Buy the Gore version if you want the ultimate in warmth and water resistance for snow caves and igloos. The inside of the foot section is slightly burlier fabric for placement of boot liners or full boots that have frozen to your feet. (happened to me!) By the way, this is not licence to crawl into your bag with crampons in place! Want the maximum in warmth/weight/compressibility? You're looking at it.

If you want the ultimate for warmth and water resistance in snow caves and igloos buy yourself and ultralight event bivy sack instead. You don't the the gore-tex shell on your sleeping bag to be your last line of defense against a wet bag in those conditions. Get real dude.

For anyone interested, here's what Western Mountaineering says about Gore Windstopper™ 830 Fabric: "Our Gore Windstopper™ fabric, manufactured by W.L. Gore and Associates, is the most weather resistant/breathable fabric available and provides the ultimate protection against moisture and condensation. The face fabric is a 273 thread count 30 denier fabric that weighs 1.1 ounces per square yard. This is the lightest and most compressible Gore Windstopper™ fabric available and the one with the softest hand. After laminating, it's finished weight is about 1.7 oz. per yard. The breathability of the Gore Windstopper™ membrane reduces the threat of condensation while remaining plenty water resistant for the needs of a sleeping bag. Use Gore Windstopper™ sleeping bags in damp or extreme conditions to prevent moisture from reducing down performance. Some winter conditions may require the use of the Hot Sac™ vapor barrier liner to provide the most optimum performance."

Just a reply to Philip's post. I share your concerns about the breathability of fabrics, but Gore Windstopper is not the same as Gore-Tex. The PU laminate is NOT present, and this allows air and water vapor to pass. Gore Windstopper is totally windproof (unlike eVent), but due to the lack of the PU laminate, you don't need to develop a temperature and humidity gradient to allow moisture to pass. The GWS is a very acceptable compromise for water resistance and breathability. And it will save you weight over a eVent bivy. At the temperatures we are talking about, you don't need complete waterproofness.


Would anyone know with experience if Marmot CWM -40F is better or WM Puma MF? Read few reviews and seems WM is most preferred but didn't come across any negative remark on Marmot CWM either. So would need suggestions from someone who has had experience with these products.

Hi Ash, I've poked around with the Marmot and I own a Puma. It depends what temp you actually need, -25 or -40. crawling into my Puma is always a treat whether it's 25F or -10F (I haven't actually slept in -25F weather). I know when I hopped into the Marmot, there was nothing wrong with it, but once you get into a WM bag, it's just way more inviting, and comfortable to be in. Also if you're looking for a highend winter bag, they aren't sold on backcountry but, Feathered Friends is in my opinion WM's only competitor. Their bags are also hand made in the USA (Seattle), and they are generally a bit cheaper, and can offer a bit more wiggle room inside. My thoughts are if you are going to spend $800+ on a sleeping bag, so with Western Mountaineering or Feathered Friends as they are the experts in this realm. P.S. the Ptarmigan EX -25 by FF is $40 cheaper than the Puma. However you can call up FF and for $50 they will overfill the foot box for you making it extra toasty.


Is this bag water resistant?

Is this bag water resistant?


Hey Garrett- Glad to see that you finally got around to the finest bags in the world. You will totally dig this bag! Here's the write up from WM- It's also got a DWR coating Microlite XP™ Our new 20 Denier MicroLite XP™ microfiber reduces the total weights of the bags in this series by 15 to 20 percent! It is the highest threadcount fabric we have ever used with over 400 threads per square inch. We have worked closely with our supplier to develop this new fabric which is highly water resistant, highly breathable, and very light weight. Its hard to imagine a more impressive combination of performance characteristics in a shell fabric. What Is Microfiber? A microfiber fabric is very water resistant because of its combination of high thread count and makeup of dense yarns. Each micofiber yarn has many more filaments than a normal nylon or polyester yarn of equivalent size. Woven into high thread count material, it becomes a fabric that really keeps wind and water out. Since there is no coating or laminate on the material, it is highly breathable. The fabric construction is responsible for weather proofness, it's not something that can wear off, wash out or delaminate. This is the most technologically advanced non-laminated weather resistant fabric available. Look for bags with a microfiber shell if you expect some contact with moisture.

It has done great shaking off condensation and an occasional light spill of water. Wasn't designed to be waterPROOF, but it also breathes much better than a goretex bag and keeps the down dryer and higher lofting because of it