Got this sweater jacket to layer under an OR Celestial shell. Great ultralight combination for most any conditions down into the teens. I'll be using the combo for hiking/climbing and the jacket is replacing a down vest that's gotten many years of use.
The jacket itself is amazingly light and well finished - the cuffs, zipper, pockets all feel right. The only drawback is the gussets at the armpits. They're just too tight. Even with only a light shirt underneath the jacket cuts into my armpits. I'm a medium with the only common problem of sleeves being too short. On this jacket, the sleeve length is good and every other measure is fine except for being pinched in the pits. An extra half inch or so through the gusset would be all this jacket needs to make it a complete winner for me.

Great jacket, the Paprika(Red) minimizes the trashbag look. It is unbelievably lightweight, packs down to nothing and I still have a hard time believing it keeps you as warm as it does.

However: I am a size Large in TNF, and had to exchange for a XL in this jacket because it was too small around the chest/back/armpits if you did anything but stand up straight.

The MontBell UL down jacket is exactly what I was looking for. For those unfamiliar with ultralight gear and clothing, don't expect lots of features. Do expect a feather weight, insulating layer that stuffs very small. Although called a "jacket" it is not suitable as outerwear in all conditions. Think of it more as a "puffy" layer worn over your base layer and under a windshirt or outer layer. It's about as warm as heavy-weight fleece without the weight. The outer shell is somewhat water resistant but you'll need a rain jacket to keep it dry in wet conditions. Bonus: stuffed into a sack or t-shirt it makes a great down pillow.

Splendid minimalism! No zipper, no pockets, nothing that adds weight unnecessarily. This jacket exists for one reason: to provide the efficient insulation of down at an absolutely bare minimum of weight. My XL in stuff sack (which it comes with, a nice touch) weighs precisely 7.4 oz and compresses down much smaller than a Nalgene bottle. I'm aware of nothing on the market with a superior warmth to weight ratio as this jacket, period. This piece of gear goes on EVERY trip, any length, any season.

I bought this jacket for my boyfriend. He normally wears a medium, but the medium was too small on him. I had to return it and reorder a large, and he loves it! He normally won't wear a jacket, even when it's below freezing out, but he does wear this jacket. He likes that it's ultra lightweight, and barely feels like he is wearing anything, but he says that it is very warm.
I think this is a great jacket, just be careful of the sizing when ordering. I would recommend ordering a size larger, if you have any doubts.

I love this jacket. This jacket is perfect for layering, backpacking or just taking along in case it gets cold because it comes with a stuff-sack and packs down real small. You have to know what you are buying before you buy it and think of your need. If you want to go light, this is an amazing jacket. If you want something that is ultra durable, look elsewhere. You sacrifice a little durability when you buy really lightweight stuff. having said that, I love this jacket and if you take care of it, it will last you for years. 6foot 170 and the large fits perfect.

I've owned this jacket for about 5 years and have used it backpacking in the cascades,rockies and alaska. It sheds light rain, drys well,and has always performed exceptionally. Because of it i have two other montbell jackets of different weights that i also wear all winter and summer sometimes

I purchased this as a mid-layer to wear under hard shell in cold weather. Have worn wool baselayer, this liner and hard shell in -10 F and was very comfortable and no smell between this and wool base! I would say I am average in susceptibility to cold being a life long resident of MN. I prefer this to fleece mid-layers as this does not bunch up under arms or around waist and the nylon shell slides easily against base layer and shell so sleeves don't get twisted during activities. Works as advertised, light weight makes it very comfortable as a layer and easy to stuff in sack and place in bottom of daypack just in case. Very happy with purchase.

This is the jacket that I have been looking for for a long time. It is warmer tham my bulky fleece and packs down to nothing. Space and weight are important to me and this peoduct is the trick.... Love It.

I love this jacket. It weights nothing compresses in a very small bag and brings you all the warmth that you need.

This is the beloved army field jacket liner concept taken to its fullest potential. Way lighter than fleece and because of the material, you don't chill in a breeze. Packs small enough that you can keep it handy for layering. I like to hike in a minimal amount of layer so when I stop I chill fast. This is just the ticket. Just don't let go of it on a windy day. Pockets are great. Collar works good. Would like to see some sort of drawstring waist for when I wear it without a shell. I am 6-2+/about 210# and wear an XL.

one of the best purchases i've made. Warm as toast and packs down to the size of a monkey fist. 'nuff said.

I purchased the MontBell untralight jacket based on its amazingly light weight. I'm always sceptical about advertised weights and as soon as the product came in I weighed it on my electronic fish scale. It came in at exactly 7 oz. as advertised. I've had it out on a 6-night trip in the North Cascades (NOCA). I am not aware of a rated temperature for this garment, but I experienced temps down to 40 or so at NOCA and I was quite comfortable with the MontBell under an outer shell garment. The construction is very good and the pockets are a big plus. After the trip I also went into Seattle to hit the gear shops and noticed that Feathered Friends (a personal favorite down garment and bag manufacturer) was offering the MontBell in their flagship store. I think that says a lot in and of itself.

Anyway, I highly recommend the garment as a warm featherweight product. It'll be in my 3-season pack from now on!

I was looking for a 3 season (Spring/Summer/Fall) down jacket for the mountains. There are days when you need just a bit more warmth without wanting/needing the big puffy coat. This lightweight down jacket is perfect. It's literally as light as a feather and is warm without being heavy or bulky. I bought the guys version so I'd have the ability to wear this over layers if needed.

I've owned this jacket for 3 years now and have nothing but praise for its exceptional quality and durablity. It compresses well and keeps the cold out. I use it mainly for summer mountain treks but it also works well as a camp layer. Check it out!!

This truly is ultralight - only 2 oz. of down and 6 oz. overall. For me, that turned out to be a bit less warmth than hoped -- equal to, but not warmer than a sweater or fleece.
My other concern is that my 34" waist felt snug in size Medium. On rechecking, for Montbell, Medium only goes up to waist size 33.
On the bright side, I saw no sign of down leakage, and liked the style and feel.
I replaced this jacket with a North Face Flash, also is size Medium, which solved both concerns, alas for more money.

I love my Montbell Ultralight Down jacket! This jackets great for the ski touring I do in the wasatch. After a long skin. Just pop this bad boy on to keep the chill away while your getting ready for the ski down. And on super cold days, just rock this guy as a layer under a shell. And your super toasty warm!! I love this jacket. Only draw back is it is made in china!

Love the jacket! I will be using this jacket for our hike on the PCT in 09. Have been using it during night walks with the dogs and cold weather days. I will always have a shell over top as the 15 denier nylon outer shell could rip quite easily. Have had no problems with the breezes going through it but higher winds can penetrate the sewing between the baffles. Absolutely light and warm. Bought this one over the Extreme light because this comes with pockets and heavier denier nylon on the outer shell (15 on UL vs. 7 on ExL)

This is an extremely lightweight jacket. Great for 3-season use in cool-to moderate night time temps. About the same warmth as a 200 to 300 weight fleece without all the weight or bulk. The new model is much improved with the zipper and two hand warmer pockets. In summer/spring/fall it is great as part of a 3 piece layering system.

I was expecting a little more loft, but it is perfect for a midlayer so i can't complain. I think they could have made it a tad longer..

Great lightweight jacket that compresses into a tiny space, insulates better than fleece and is a good wind block in moderate winds.

Great jacket. This is just the additional layer that I needed for my early morning hikes.

I received this ultralight down jacket (I consider it more of a sweater)and it went straight into my pack for a multi day show shoe trip to Clouds Rest in Yosemite. In the evenings I slipped this jewel of a garment on with my vest and shell and was toasty warm as I gazed at the stars. At 7oz. this garment is lighter that the polartec 100 top I used to carry and so much warmer. It has become one of my favorite pieces of gear. It's like Diamonds. Gotta love Montbell.

This is an excellent liner for almost any coat or jacket. It is that one middle layer that you will shed by mid-morning on a typical South Carolina winter day.
Also it is very comfortable solo around the house in the evenings.

I took this jacket instead of fleece on a three week hiking trip to Patagonia, and it worked great. It's much lighter, warmer, and more packable than fleece. The only bad is that it shed down for the first week and a half so whatever was under and over it got its fare share of feathers. I think that it might be because I was stuffing it into the stuff sack and keeping it in my pack between wearings. Anyway, now the shedding seems to have stopped so that's not an issue anymore. Bottom line -- it's warm and incredibly light and packable. This is my new favorite layering piece.

I frequently hike in the morning starting at dawn. During the winter, it can get down to freezing at dawn (southern cali). I bought this jacket as a lightweight addition to my usual vest & wind shell. It works perfectly and when it warms up, I can stuff it into my pack and not even notice the weight. It seems too thin, but the high loft down really does the trick.

The warmth:weight ratio for 800-fill down is unmatched, and nobody makes a lighter, more compressible jacket than MontBell.

Now that I have a MB Ultraweight Down Jacket in my compact mandatory clothing quiver, I can go confidently into the backcountry with just a top layering of polypro base, mid-weight fleece sweater and a Gore-Tex shell.

Awesome Jacket!
SUPER light and amazingly warm. I saw this on a buddy and ended up ordering it the next day. I haven't done any hikes in it yet, just the city thing so far, but I know it will be packed with me often!
A must have!

I have one of these and bought one for my boyfriend too...he loves it!!! it's the perfect weight for chilly fall days, or for layering on the slopes or back country!!!

best layer i have ever owned

I am extremely pleased with this garment and I believe may be one of the best outdoor products I've ever owned. There are warmer down coats but this "sweater" type under-layer works so well and can be combined with any type of shell or outer coat. I tried it one day with one of my real down coats and and the concept of "cold" was no longer part of my vocabulary. Oh yeah, for winter camping, it's the best "night shirt" one could wear when nature calls and it's 15 degrees outside of your sleeping bag. One thing about the jacket- if you big (you know what I mean) XL may not be XL enough. Maybe OR Transcendent Down Jacket (nice) or Patagonia Down Sweater Jacket (very nice) are cut a little larger and are probably just as good.

Size lg weighed in at just a fraction over eight ounces. No waist draw string, and only elastic at the wrist. This is for the minimalist, packing a lot amount of warmth for it's weight.
From reading other reviews I was worried about the sizing. I am 6'1 and 170 pounds. I found this size lg to fit me pretty much the same as other outdoor gear companies such as North Face, Mtn Hardwear, Arcteryx etc..

Absolutely the best and worth every penny. Essential for travel (business too), as it has to be the lighted, most compact, warmest under jacket ever.

The jacket is very stylish--you can't tell whether it's Montbell or the internationally famous brand Moncler. Extremely light--a 15mile/hr wind can blow it in the sky. Material is extremely soft--tends to be a bit fragile. But to my surprice, it's durable so far.

Yes. it definitely runs smaller. Order one size up.

Montbell makes some of the best ultra light garments. I got this to go with the UL Down Pants. Fit is right on and the weight is just a hair over 7 oz for the jacket. Packs down super small and keeps me warmer than a fleece of the same weight. Quality materilas and build.

I took this jacket out almost every time I went into the backcountry for skiing last season. Takes next to no room in the pack, and is warm when combined with another layer. Probably best not to wear this as the outer layer when skiing through the Scourge of the Wasatch - Gambel Oak - it will rip. Not that that is a bad thing - gave me an opportunity to add some duct tape for coreness.

Never pull the feathers out of your jacket or sleeping bag. This is a common mistake. Simply grab the feather from the inside of the jacket and pull it back inside. Don't pull out the down.
My patagonia down sweater has the same problem.

Now pick yer' size & color and click "Add to Cart". You will no longer need to consider this piece of gear. (unless maybe you prefer the Patagonia version, which is nice too... Oh drats!)