2015 Ski Guide2015 Ski Guide


Comfort is key.

Whether you are doing a weekend trip into the Sierras or backpacking through Europe, The Sea To Summit TkIII Down Sleeping Bag is roomy enough to let you get a good night's rest. With the TkIII, you don't have to give up warmth for comfort or feel claustrophobic just to keep from freezing.
  • The 650-fill down gives you superior loft and insulation for a better warmth-to-weight ratio than anything on the planet
  • Breathable 2D PermaShell is lightweight, down-proof, and vapor-permeable to help reduce condensation
  • Tapered design mixes the roominess of a rectangular design with the warmth of a mummy bag
  • Side baffles keep insulating down in the right places so you don't end up with cold spots
  • The large security pocket lets you keep your wallet, passport, and your media player zipped inside with you
  • Full-length zippers with draft tube let you convert this bag into a flat duvet or pair it with another bag when you need room for two

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Review Summary
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1 3
0 2
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Sea To Summit TkIII Sleeping Bag: 12 Degree Down

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Here's what others have to say...

Does this bag use their Ultra-Dry down?

Posted on

Does this bag use their Ultra-Dry down?

Can sleeping bags of two different lengths...

Posted on

Can sleeping bags of two different lengths be joined together?

5 5

Worth Every Penny

  • Gender: Male
  • Familiarity: I've used it several times

The zipper is snag-proof. That is half of why I got this, and it really is consistently smooth.
It is the perfect cross between a light backpacking mummy, and a rectangular bag. I like to be able to put pants on in my bag when its cold in the morning, something that is really difficult in a mummy bag. This has the right amount of space without being bulky. The temperature rating seems true, though I haven't tested it below freezing, I did wake up sweating (naked in bag) at 35 degrees at 11,000 ft. With a good liner it might be used as 4 season bag.
It compresses really well, and fluffs up well. The compression sack it comes with is actually too big, it could pack even smaller, but I can't complain seeing as most bags don't include a compression, laundry and storage bag.

5 5

So far so good

I bought it because I am going to be traveling through Europe and Asia for the next year. I'll be in the Alps during the beginning of winter, staying indoors and I'll be at the base of the Himalayas from January through May. I'll be sleeping indoors there too so I wont need anything crazy, but I've been told the place that I'm going in northern India doesn't have heaters, so... One of my main concerns was that it packed small, I don't want to lug a huge bed from Europe through Asia. It barely fits into a small sea to summit dry stuff sack which is a little smaller than 16"x11". I can get that to fit on the outside of my bag. The stuff sack that they give you is way too big I think. I'm going to use it to keep my pack organized. It really is shocking that I can fit this thing in the small stuff sack because while it is out on my bed it pretty much covers the whole twin bed like a down comforter. I'm staying in places with beds so I wanted to be able to unzip it and use it like a comforter, it does that perfectly. And when it is zipped up I don't even notice really because there is so much room inside. Granted I'm a pretty small guy, 18" shoulders, 16" waist, and 5'7" height so I get lost in the thing. The down is so fluffy I pretty much float on it when I first crawl in. It's like a bed all on its own, a bed that stuffs down to the size of a travel pillow. Now that's the kind of bed I want to travel with. The material that it is made of is sold. The zipper doesn't have any trouble zipping up, the rip-stop works great. I do get a little frustrated with the zipper while it's at the bottom after you completely unzip it and want to zip it back up again. It's hard to get the two sides of the teeth to line up. They do put a little piece to grab on to to help you out though. I still find it unduly challenging, maybe it's just me. I'll let you know how it fairs up when I take it around the world with me.

5 5

great quality!!

  • Familiarity: I've used it several times

I hate the restrictive feeling of a mummy bag and this is a perfect solution! I can tell you Sea to Summit is pure quality!!! It seems true to its temperature rating, and I have never gotten cold (slept comfortably when it was in the low twenties). Finally a zipper that doesn't snag!!! I feel like this bag will last me a long time and am super happy with it.

4 5

Pleased with the bag

The TK3 was my choice of semi-rectangular bags. I like to be able to move inside the bag and wanted the versatility of being able to zip the bag partially or completely open for ventilation. I've slept in temps plus or minus freezing this winter and stayed comfortable. As pointed out, the bag is well made and comes with useful accessory storage.

It would be perfect for me if it had slightly more room across the shoulders--it's a bit restrictive--and if it had some method of holding the lighter-insulated bottom of the bag to the pad -- a sleeve like my Big Agnes summer bag or attachment points for straps to hold the bag and pad together. If the bag turns with you, rather than you inside it, your back is 20% less insulated. There are hanging loops on one side for airing the bag, so I may try to sew some on the opposite side for strapping the bag and pad together. With slightly more shoulder room and a bag/pad system approach, the bag would be wonderful. Listening Sea to Summit folks?

what is the length of the long version?

Posted on

what is the length of the long version?

Responded on

Max User Height: (short) 5 ft 7 in, (regular) 6 ft, (long) 6 ft 8 in

5 5

Sea to Summit did it right!

Bought this for my wife to use backpacking and hut trekking: what a great choice! Right out of the box I could see the thought and care that went into this bag. The accompanying storage,stuff and wash bags are sturdy and well designed. The bag itself has a tough exterior and soft lining. It is roomy and closes down to hold in the heat. The zippers are snag-proof and sturdy...everything in this design seems to be meant for long-term, no-hassle use. Stuffing down the bag, it got to the size of a child's soccer ball: a little bulkier than I thought a bag of this size and rating should be, but not bad. This is a great purchase!

Sea to Summit did it right!
5 5

High quality bag

My wife bought me this bag for Fathers Day. I'm just back from a week backpacking, most of which was spent between 11 and 12K elevation. I don't know the low temps however there were hard frosts most mornings so it was below freezing, probably by several degrees. This back is designed for someone who turns inside the bag, not with the bag like in a true mummy. 60% of the down is on top so if you turn with the bag your back will get cold if it is a cold night. I never got cold. I was just wearing undies and a light polar tech top. I used to wear mid weight long johns in my old bag. I'm a cold sleeper. I went to the Sea to Summit web page to learn about their products. They use the EN temperature rating system and their comfort temp is 23F with 12F as the lower limit. If you are a cold sleeper you will probably get cold at 12F unless you had on some clothes in the bag. It is duck down. I did some research before buying and in general goose down is better, however good quality duck down is just fine and the best down is eider down which is duck down (this bag is not eider down though). Sea to Summit sends a down quality certification with the bag as well as a compression stuff sack (nice), a storage bag and a wash bag with instructions on it on how to wash the down bag. The zipper never snags and the bag lofts nicely when you unstuff it. I'm 5'11'' and had to get the long length. My shoulders were almost out of the bag on the reg length. The hood works well if you are just a back sleeper. I use the hood to enhance my pillow since I am a side and stomach sleeper. This is the best sleeping bag solution I've found for an active sleeper who does not like the confinement of a true mummy bag.