20F Classic Sleeping Bag

44 reviews
$359.00 Weight 16.6 oz / 471.0 g

Lead Time Ships in About 2 to 3 Weeks

When the temperatures drop, stay warm and cozy with our award-winning Classic Sleeping Bag. Striking the perfect balance of warmth and weight,​ our ultralight Classic Sleeping Bag features a 3/4th length zipper on the bottom, combining the best aspects of a down quilt and a down sleeping bag, all at an unbeatable weight!

Includes a Free Zpacks Roll Top Dry Bag for Storage! A $30 value!

You can also get a similar bag as a zipper-less Solo Quilt​, or as a Full-Zip​ version that includes a draft tube.

  • Constructed with DownTek water-resistant 900 fill power goose down which stays dry 90% longer than untreated down. It has C0 water repellent with no PFOA or PFOS. Our down is responsibly sourced and is 'Responsible Down Standard' Certified.
  • Each compartment is overstuffed with 30% more 900 Fill Power Premium Goose Down than is necessary for maximum loft to account for any future down compression.
  • Vertical baffles on the upper body keep down from migrating to the sides. Tightly spaced compartments help keep the down evenly distributed so there are no cold spots. There are no "sewn through" seams.  
  • Our rectangular foot box is roomy, and fits the shape of your feet comfortably when lying on your side, on your stomach, or on your back with your feet angled out in a relaxed position. 
  • Black fabric on the inside for quick drying. Both the liner and the shell are treated with C0 durable water repellent to resist rain spray and body moisture. 
  • 3/4 Length Zipper extends to your calves. The zipper is positioned on the bottom of the bag allowing for multiple sleep set ups.
  • The bag can easily be opened up for venting in "quilt mode". Most of the time you probably won't even use the zipper.  
  • Since the zipper is underneath you no draft tube is necessary- that means less weight and much less chance of a frustrating zipper snag.  Getting in and out is as easy as turning the zipper to the side, or just slide in or out the top of the bag.
  • A flat clip at the top of the zipper keeps the zipper securely closed. Or use the clip alone with the zipper opened for venting.  
  • An Elastic cord can be cinched tight around your neck to keep out drafts, or pull the bag up around your ears. This bag does not have a hood- wear a warm hat, or a Goose Down Hood, or size up in length if you want to pull it up around your head.  
  • Roll Top Dry Bag is included, and adds ~.9 ounces (25.5 grams) to the listed weight. The dry bags are a comfortable fit and can be compressed smaller by squishing the contents and rolling the top down more.
  • All Zpacks gear has a two year limited warranty against defects in materials or workmanship. Please see our return / warranty policy.

A printable .pdf version is available here.

ISO Rating

While our sleeping bags and quilts have not been tested for their International Standard Organization (ISO) rating, we estimate based on feedback and use they are closest to the middle of the "Lower Limit“ of the ISO ratings.

.51 oz/sqyd Ventum Ripstop Nylon

The inner and outer shells of our Sleeping Bags and Quilts are both made from this super light, high quality, 7 denier fabric that weighs in at just .51 oz/sqyd (17 g/m²). 

Featuring a high quality "C0" durable water repellant (DWR), this ripstop and tear resistant material can also handle light mist and dew (but is not waterproof).

Ventum nylon cuts the wind while still allowing for excellent vapor transfer and breathability. With a soft texture, Ventum is not sticky or plastic feeling like some other fabrics in this weight range.

The material is down and mosquito proof and is an excellent choice for wind shell clothing and sleeping bag shells.

Made in Japan.

DownTek 900 Fill Power Water Repellent Goose Down

DownTek 900 Fill power goose down has a "C6" water repellent which allows it to stay dry over 90% longer than untreated down. The water repellent is PFOA and PFOS free. It is 'Responsible Down Standard' certified, ensuring that the animals are treated humanely. Goose down is a byproduct of the goose meat industry.

A printable .pdf version is available here.

Click here for full instructions on how to wash our down sleeping bags and quilts.

Click here for instructions on how to properly clean and care for your zipper.

Customer Reviews
5.0 Based on 44 Reviews
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Filter Reviews:
Jenny M.
New Zealand New Zealand

very comfortable

Grant S.
Australia Australia
Light weight and warm

I’ve just used this 20F bag a few times so far, but loving it already. Far lighter than my previous bag (similar warmth rating), packs down small and is toasty warm. On warmer nights I’ve used it more like a quilt with the zipper open. Then zipped up in colder conditions it really retains the warmth. Not missing the hood of my previous mummy bag (makes me realise I never really used it). Sizing is spot on.

William B.
United States United States
Wife Loves It

Great experience. I got the size wrong and had to return/reorder, but I had the replacement in a week

Claire L.
United States United States
Kept a native Floridian warm...

I'm one of those people who turns blue when the AC is even just a degree or two under 70. When I moved from Florida to North Carolina 8 years ago, this posed a problem. I had no cold weather clothes or gear and so despite loving the outdoors, I spent multiple months of every year as basically a shut-in. This year I decided to finally fix the problem and buy the good stuff, but I was skeptical that it would truly allow someone like me to stay warm in freezing temps. So when my Zpacks 20F Classic arrived a few weeks ago, I decided to take it for a test run to find out. Went over to Pisgah National Forest to backpack in and camp close to a waterfall on a subfreezing night--my thermometer read 28F at the lowest that I saw (this is very cold for someone like me!). I was so shocked at how well this bag protected me from the cold, and was so comfy and cozy too. While I was inside the bag I totally forgot how cold it was outside, and was in for a rude awakening every time I got out of the bag to go check on my overnight astrophotography project. I usually sleep in a hammock in the summer months and so I'm still upgrading my tent camping gear piece by piece--I'm still using a cheap-o sleeping pad from Amazon underneath the bag--didn't matter, this bag was so comfortable. I'm a 5'7 130-lb. thin(ish) athletic female - I got the Standard length to ensure I could burrow down inside when I wanted to. Got the Medium to make sure I could side-sleep and also let my husband use the bag sometimes (I was so happy with this 20F bag that I just bought a 2nd Zpacks Classic in 10F, so there will be times I use that one while the husband uses to 20F. He's more cold-acclimated than me...) Anyway, if it were for my use only, I probably should've gone for the Slim because I had extra room in the Medium even when side-sleeping, but given our uses I think these choices were perfect. Finally, as a nature and wildlife photographer I am frequently already loaded down with camera gear when I backpack and so weight is a very important concern as I upgrade equipment. I can't believe how something so warm can be so lightweight. This upgrade has taken a ton of weight off my back, even over my summer hammock camping setup. I think this native Floridian is finally becoming a cold-weather convert! Now I can't wait for even colder temps to try out the 10F!

Brad J.
United States United States
20 degree Sleeping Bag

Fantastic product. I am huge fan of Z packs and this 20 degree bag is perfect for any of the off seasons. Was using a western mountaineering quilt for a couple years but decided a few more ounces for quality sleep and comfort is well worth it. Don’t want to wake with cold uncovered body spots any more so after making the switch I am officially sticking with a zipper and the full length bag. Very happy with the purchase.