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Hands-on Gear Review

ZPacks 20 Degree Review


Ultralight Sleeping Bag

  • Currently 4.0/5
Overall avg rating 4.0 of 5 based on 1 review. Most recent review: November 1, 2015
Price:   $390 List
Pros:  High warmth-to-weight ratio; many length, width, and custom options
Cons:  Not as versatile as a quilt (fixed girth doesn't adapt to clothing/body type), narrow footbox
Manufacturer:   ZPacks
Review by: Brandon Lampley ⋅ Review Editor, OutdoorGearLab ⋅ November 1, 2015  
The ZPacks 20 Degree hoodless mummy bag is the second highest scoring product in this year's ultralight sleeping bag review, and delivers one of the best warmth-to-weight ratios. This impressively light bag envelops you in 900 fill power down whether you sleep on your back, tummy, side, or have to bivy sitting up. The regular girth, medium length version that we tested tipped the scales at 17.2 ounces, and can keep you warm into the high teens with a warm hooded jacket. The only significant downside to our zippered test model is the fixed girth when zipped up, which doesn't allow for much flexibility to adjust the amount of warm clothing worn to bed.

If your focus is building an ultralight backpacking system appropriate for a thru-hike of the Appalachian or Pacific Crest Trails, and you want pare your base weight down to less than 10 lbs, the Zpacks 20 Degree is one of two bags that we recommend for hikers that can afford them. We feel the Katabatic Gear Palisade 30, our Editors' Choice winner, is the best choice; its adjustable girth is a major plus compared to the ZPacks. Most of our testers found it warmer as well. But some folks still prefer a mummy bag, and the ZPacks 20 Degree is the lightest and warmest mummy we tested. If the price tags of these two models are prohibitive, check out our Best Buy Award winner, the Enlightened Equipment Revelation 20. It is nearly as warm, very versatile, and much more affordable.

RELATED: Our complete review of ultralight sleeping bags

  • Photos
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OutdoorGearLab Editors' Hands-on Review

The ZPacks 20 Degree hoodless mummy bag delivers excellent warmth and is very light. Indeed, these qualities make it a perennially popular choice of long distance ultralight hikers. However, compared to other products in this review, it is not as comfortable or versatile.

How to Get It:
ZPacks sleeping bags, shelters, and backpacks are custom made by the small manufacturer in Florida and are not available from online retailers or outdoor stores.

Get it online at: ZPacks.com.

Performance Comparison

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If you're after the lightest ultralight bag that's warm enough for three-season use and thru-hikes, this is an excellent choice. Comparable products are more comfortable and versatile, but not quite as light.
Credit: Brandon Lampley


We found the ZPacks 20 Degree sleeping bag we tested to be the second warmest model of the bunch. Only the Katabatic Gear Palisade (which is a closed footbox quilt) was warmer for our testers, and not by much. We awarded both a 9 out of 10 score. In the Palisade, we were always optimally positioned on top of our sleeping pad for warmth. In contrast, in the ZPacks mummy our testers who are active sleepers often slid off their sleeping pad onto the heat draining ground. In addition, the Palisade's adjustable girth gives you the option to wear a much warmer large down parka to sleep in if you really want to push its use into cold weather. That said, compared to the other fixed girth mummies we tested in this review, the Zpacks is definitely warmer.

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This is the second warmest bag we tested. On this fast and light trip, our lead tester only brought a very small closed cell foam pad. Pair this bag up with a full-length, ultralight sleeping pad to achieve the most warmth.
Credit: Brandon Lampley

Weight & Packed Size

ZPacks has made its name producing very light and functional equipment for backpackers. Our test model, the medium length and regular girth 20 degree rated bag, weighed in on our digital scale at 17.2 ounces, and the included rolltop Cuben fiber stuff sack .8 ounces. None of the three bags that are lighter than the ZPacks are nearly as warm. In fact, the Palisade is the only model with a similar warmth-to-weight ratio. This ZPacks bag was an award winner in our old review, largely due to the impressive warmth-to-weight ratio.

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Weighing in at 17.2 ounces on our digital scale, this is the lightest model we tested appropriate for true three-season use. The warmth-to-weight ratio rivals that of our Editors' Choice winner and it comes with an AWESOME stuff sack.
Credit: Brandon Lampley

We measured this model in the included cuben fiber dry bag stuff sack at 6 x 12 inces. This is the best stuff sack that we've ever seen included with a sleeping bag. It's waterproof, durable, and is functionally airtight. The same sack that comes free with your bag costs $21 on ZPacks' online store.


Fixed girth sleeping bags like this one suffer from limited versatility. They can't increase in girth to adapt to additional clothing layers (i.e. a winter parka). What this bag does have going for it is a relatively long zipper, down to knee level. Leave it unzipped for warm nights. Comparatively, the Palisade's design and pad attachment system make it more adaptable to cold temperatures, and fully-opening quilts like our Best Buy winner Enlightened Equipment Revelation 20 are versatile for both colder and warmer nights.

Many custom options can increase this bag's versatility. Since this is a notoriously minimally sized bag, choosing a larger version will increase your ability to wear warm clothing to sleep.


This bag's focus is warmth at the minimum weight, not on offering additional comfort-focused features. The neck closure is very simple, and not as comfortable as the more refined (and a little heavier) designs used by the Katabatic Gear Palisade or the Feathered Friends Flicker.


This hoodless mummy bag uses a 48" #3 YKK zipper for closure with a single pull. It is sewn in at the bottom, rather than having another pull for ventilation. Unlike the Mountain Hardwear MTN Speed 32 which has a major zipper flaw, the ZPack's zipper is securely (if a little haphazardly) sewn and secured. Unlike previous versions of this bag, a small plastic buckle completes the neck closure. Previous versions used a velcro tab here; we think the buckle is superior. ZPacks intends for you to sleep with the zipper underneath you, hence there is no draft tube, but you can opt for a custom draft tube if you want to sleep with the zipper on the side rather than underneath.

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ZPacks has upgraded the neck closure of this model with a secure buckle. It is not a comfortable as some others we tested, but functional and light.
Credit: Brandon Lampley

A small string with a free-floating cord lock forms the neck cinch system. While it works well sealing in warm air, it does not have a comfortable baffle inside like the Palisade's. A small Cuben fiber reinforcement patch here prevents the string from wearing on the super lightweight shell fabric.

Very light Ventum Ripstop Nylon and premium 900 fill power down, along with the slim cut, create this bag's exceptionally light weight. Additionally, 360 degree continuous baffles give you the option to shift the down around to where you need it for warmth. We found the footbox of this bag very small; if you have big feet, you may find this uncomfortable and cold. There is one hang loop sewn into the bottom of the bag under the logo patch.

Best Applications

This is an excellent ultralight sleeping bag for backpacking, bicycle touring, or summertime alpine climbing if you prioritize warmth at the lightest possible weight.


At $390 this is an excellent value if your priority is warmth-to-weight ratio and comfort and versatility are less of a concern. One of our testers has used this bag for 3,000 miles of hiking with no loss of loft, fabric tears, or problems with the zipper.


While we find several other bags in our ultralight review more compelling due to greater comfort and versatility, there's no doubt about it, the ZPacks 20 Degree sleeping bag is one of the two warmest and lightest for three-season ultralight backpacking. Only the Editors' Choice Katabatic Gear Palisade scored higher in this year's review.

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When our lead tester was putting together a sub-15-pound pack (total weight with food) for a two-night mountain traverse with rough bivies, the exceptional warmth-to-weight ratio of the ZPacks 20 made it his top choice.
Credit: Brandon Lampley

Sizing, Accessories, & Other Versions

The bag is available in three widths and four lengths, which allows you to get the best fit for your body type and specific end use. On ZPacks' website, you'll find instructions for measuring your chest plus arm girth. Don't feel bad if you find the Wide or even X-Wide will fit you best when wearing an insulated jacket, as ZPacks bags are cut very slim. Consider up-sizing as well if you have big feet and burly legs.

ZPacks offers a handful of custom options for this bag. The standard zipper length is 3/4 and is designed for you to sleep on top of the zipper in cold conditions. If you aren't comfortable keeping the zipper underneath, you can add a draft tube (0.8oz) for $20. Ultralight webbing straps, much like those found on quilts we've tested, can replace a zipper. Or you can drop the zipper entirely and sew the bag up, similar to the Feathered Friends Vireo.

ZPacks 40 Degree (Medium Length, Regular Width)
  • Cost - $350 ($40 less than the 20 degree bag)
  • Weight - 11.4 ounces (5.3 oz less than the 20 degree bag)
  • 900 fill power goose down

ZPacks 30 Degree (Medium Length, Regular Width)
  • Cost - $370 ($20 less than the 20 degree bag)
  • Weight - 14.0 ounces (2.7 oz less than the 20 degree bag)
  • 900 fill power goose down

ZPacks 10 Degree (Medium Length, Regular Width)
  • Cost - $410 ($20 more than the 20 degree bag)
  • Weight - 19.4 ounces (2.7 oz more than the 20 degree bag)
  • 900 fill power goose down

Goose Hood
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  • Cost - $65
  • Weight - 1.3 oz
  • This hood is the perfect complement to your ultralight down quilt
  • Wear it by itself on cold mornings

Brandon Lampley

OutdoorGearLab Member Reviews

Most recent review: November 1, 2015
Summary of All Ratings

OutdoorGearLab Editors' Rating:   
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Average Customer Rating:     (0.0)
Rating Distribution
1 Total Ratings
5 star: 0%  (0)
4 star: 100%  (1)
3 star: 0%  (0)
2 star: 0%  (0)
1 star: 0%  (0)

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