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Open up some pack space with this stuff sack.

Make your sleeping bag, down jacket, or clothing smaller and more compact with the Sea To Summit Ultra-Sil Compression Sack. This ultralight stuff sack features four webbing cinch straps to compress your gear and make more room in your bag or duffel. The flip-top lid prevents straps from tangling and the slick finish makes for easy packing.

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Sea To Summit Ultra-Sil Compression Sack

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Here's what others have to say...

Unanswered Question

Hi- my husband and I have the Slumberjack -20 sleeping bag and are wondering if any of these would fit such a bulky bag. Also, how much can we realistically expect it to compress down in these? It's a great bag, especially for the price, but extremely bulky, especially for some of trips we are planning for the future. It would be awesome if we could use them but make them much smaller and thus easier to pack and haul around! Thank you!

5 5

For sleeping bag

  • Familiarity: I've put it through the wringer

I bought a 14L/M to store my Sierra Designs Rosa sleeping bag during a backpacking trip. It really condensed my bag down and fit perfectly at the bottom of my pack.

4 5

Does the trick

  • Familiarity: I've used it several times

This sack is light and packs down nice. Basically it does its job perfectly. I bought the 14L M. I used it for a 20 degree montbell ultralight down bag. S would have done the trick. If anything I'd say it would be more pack friendly if it was a little less wide and a bit longer.

is it waterproof?

Hey Caitlin,

This bag doesn't have taped seems and so is only water resistant. Check item number STS000E for a water proof option.

Feel free to ask me any other questions!


What size is best for The North Face Superlight Sleeping Bag: 0 Degree Down? (Regular size) Thanks for your help!

Get the Large for that bag!

Feel free to hit me up at or 801-736-6398.

5 5

Great for a sleeping bag!

This works perfectly with my 0° waterproof/breathable shell down sleeping bag. It's superlight, barely weighs anything.

I have a 19 degree REI Igneo sleeping bag. Would one of these work for me? If so, which one...?

Yes this would be a great option for you. I would recommend a 20L for you (size large).

5 5

Perfect for sleeping bag

  • Familiarity: I've put it through the wringer

Great compression dry sack for my down sleeping bag, and the straps really allow you to compress the items into almost nothing.

Will the mtn hardwear ratio 15 degree bag fit in a medium? Thanks


Stuff Size: 8 x 15 in for the Ratio 15 bag. That will fit in the Medium sack size.

What size compression bag would I use for the following?
Big Agnes Big Creek Sleeping Bag: 30 Degree Synthetic

The stuff size for that bag is 9x10, so a medium or Large should work. If you go with the medium, it might be a bit of a chore to stuff the last bit of the bag in. But it will probably compress better. Either would work!

5 5

Quality Stuff

  • Familiarity: I've used it once or twice and have initial impressions

I bought this while on the text line with a rep after asking for a recommendation to stuff the Northface Basalt Large sleeping bag.

I find the sizing of Compression Bags utterly confusing. Sml, Med, Lge. Litres, Inches etc.

This works perfect for my bag and the amount of compression is impressive. It extremely lightweight and thin material but seems to be very well constructed as I tend to pull hard on the straps.

5 5

I've purchased 3 of these now.

  • Familiarity: I've put it through the wringer

I now own 3 Sea To Summit Ultra-Sil compression stuff sacks. Or I should correct that and say I now own two, I "loaned" one to my hiking buddy to use as a stuff sack for his Marmot sleeping bag. Somehow I don't think I'll get it back.
There are three things I love about these Sea to Summit stuff sacks:
1. They are incredibly light compared to other similarly sized stuff sacks and lighter than the "claimed weight" - on my postal scale the size small weighs 2.2 ounces and the size medium, 2.6 ounces.
2. The workmanship is impeccable. Although made with lightweight fabrics and webbing, I've never seen so much as a frayed stitch on any of my stuff sacks.
3. They start large (bigger than you expect from the specs) and easy to cram your "whatever"* in (*clothes, sleeping bag, etc) - then you can leverage the straps to compress the load down to the smallest possible size (i.e. when what's inside is compressed to where it's as hard as a rock).
I use the size "small" compression sack for my Nemo Nocturne 15 sleeping bag and I recently purchased a size "medium" sack for my Mountain Hardware Big Bang SL -20 bag, which is a HUGE sleeping bag. The Sea to Summit sack compresses down to little more than half the size of the stuff sack that came with the bag (and that stuff sack also weighs more than 5 ounces).
All in all this is a great product, very typical of all products I have owned from Sea to Summit.

4 5

Not as durable as I'd like

  • Familiarity: I've put it through the wringer

This compression sack is wonderfully lightweight and compressed my sleeping bag well. It's also slippery sil-nylon which makes it easier to slide in and out of a backpack. Unfortunately, the top seam blew out after only two seasons of light to moderate use. I can still use it but my sleeping bag poofs out a little through the hole (and it's now less water resistant because of the hole.) It's a little disappointing because I don't believe I mistreated it at all. Still, I like it enough that I might buy another one someday and hope the same thing doesn't happen all over again.

I have Western Mountaineering Puma Super...

I have Western Mountaineering Puma Super MF Sleeping Bag: -25 Degree Down what size of stuff sack do I want?

I'm guessing a size medium will work just fine. That's what I use for my Mountain Hardwear Big Bang SL - 20 bag, which is a 650 fill down bag and therefore probably not as compressible as your WM bag.

I have a 20* bag that weighs 2# 15oz and...

I have a 20* bag that weighs 2# 15oz and measures 32"x80" any suggestions on compression bag size?

Generally speaking you want a compression bag that is sized to match the original "stuff size" of your sleeping bag. If you look up your sleeping bag online, they usually list "stuff size" ... or you could just stuff it in its sack and then measure.

5 5

Good Compression Sack

I actually bought this by accident thinking it was the waterproof version in the small size for stuffing my clothing. I'm happy to say that I'm really glad I bought it because it's worked out very well. It's quite durable and water resistant. I was hiking for 4 hours in the rain and my bag was soaked through. Luckly all my sleeping bag and clothes were in eVent dry sacks. I did keep some clothing in this and they were bone dry as well. It's not waterproof but seemed to do the trick for me. Very happy with the purchase.

What size sack do I require for a Marmot...

What size sack do I require for a Marmot Never Summer Membrane 0 Degree sleeping bag?

I agree the medium is the way to go. I have the 0 degree lithium and it fits well in the Medium.

5 5

Delivered what it promised.

It was supposed to be a good compression sack. It was a good compression sack.

5 5


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

this compression sack does what it is suppsed to and holds up under pressure..even in Mongolia

5 5


  • Gender: Male
  • Familiarity: I've put it through the wringer

I have a small for a 32 degree down bag and a XL for a 15 synthetic. Both compress the bags as small as possible. Whatever few ounces these way are made up by having more pack space and thus less need for a bigger and heavier bag. I've beaten mine up good and sat on them and they are solid. I also stuff these with clothes and use as a pillow when backpacking with a fleece pillow case over it. Going to try an eVent model with my new down bag but these are great.