The Zpacks Mummy Sleeping Bag is a lightweight, zip-around sleeping bag that can be a versatile piece of backcountry gear when you’re looking to save weight in your kit.
It is a traditional mummy bag with a hood and a full zipper that extends the length of the sleeping bag’s side and then around the footbox – allowing the bag to be laid open flat like a quilt. The bag has a 7D Ventum ripstop nylon shell with a durable water-repellent (DWR) finish, uses 900-fill power goose down, and is available in two temperature ratings, 10°F / -12°C and 20°F / -6°C.
Here’s everything you need to know about the Zpacks Mummy Sleeping Bag (and probably a little more).
Pros and Cons
+ Zpacks finally has a traditional mummy sleeping bag
+ Ample wiggle room – even in standard width
+ Can be completely unzipped and laid flat
+ Two-way zipper allows you to open the footbox only
– No interior stash pocket
– Shell material is thin/delicate
– Hood lies flat when not cinched up
– No draft collar around head hole
– Nowhere to try locally – no free returns
The Zpacks Mummy Sleeping Bag comes in two temperature ratings, three lengths, and two widths for a total of 12 different combinations (48 if you count the four different colors). Below, I will use the specs for a 20°F / -6°C, medium length, standard width sleeping bag (unless otherwise noted).
- Weight: 23.2 oz / 659 g
- Temperature Ratings: 10°F / -12°C, 20°F / -6°C
- Fill Power: 900 goose
- Fill Weight: 15.6 oz / 442 g
- Packed Size: 7 x 13 in / 18 x 33 cm
- Widths: Standard, Broad
- Lengths: Short, Medium, Long
- Baffle Direction: Vertical at torso/hips, horizontal at footbox
- Measurement at Shoulder: 60 in / 152.5 cm
- Measurement at Hip: 60 in / 152.5 cm
- Measurement at Feet: 40 in / 101.5 cm
- Inner Shell Color: Black
- Inner Shell Fabric: 7D Ventum ripstop nylon with durable water-repellent (DWR) finish
- Exterior Shell Colors: Black, Blue, Green, Orange
- Exterior Shell Fabric: 7D Ventum ripstop nylon with durable water-repellent (DWR) finish
- Foot Box: Rectangular
- Stuff Sack Included: Roll-top dry bag (.9 oz / 25.5 g)
- MSRP: $519 to $579
- Warranty: “2-year limited warranty against product failure caused by manufacturing, material, and design defects”
The Weight: The regular length, standard width, 20°F / -6°C version of the Zpacks Mummy Sleeping Bag is 23.2 oz / 659 g making it one of the lightest mummy options available. Of that weight, 15.6 oz / 442 g is the 900-fill power goose down. This puts it on the lighter side for 20°F / -6°C mummy sleeping bags (as far as the amount of down insulation in the bag goes), but there are still sleeping bags (advertised) as 20°F / -6°C bags that weigh less (and with less fill).
The Comfort: The Zpacks Mummy Sleeping Bag is comfortable – even when zipped all the way up with the top drawstring pulled tightly around my neck. Despite having just the standard width version (as opposed to the broad), I feel like I have plenty of space to move around and/or lay on my side – even with the standard width; there is a broad width version as well. The only point of constriction is the footbox – which is notably narrower than the rest of the bag.
The Stuff Sack: Don’t you hate it when you buy an expensive tent and then they charge you $80 for a ground sheet? Or when you get a $500 sleeping bag and you don’t even get a stuff sack with it? Fortunately, the Zpacks Mummy Sleeping Bag comes with a roll-top Dyneema dry bag (i.e. a very good stuff sack) that, if purchased separately, would cost you $35. The stuff sack fits the bag nicely; my only complaint is the pointed corners. I can’t seem to stuff the bag deep enough to make use of them and they just end up hanging out with empty space (see photos above for detail).
The Shell: Both the interior and exterior shells of the Zpacks Mummy Sleeping Bag are made with 7D Ventum ripstop nylon with a durable water-repellent (DWR) finish. This is one of the things that allows the bag to be so light; the shell weighs 7.6 oz / 217 g. Don’t be surprised when it starts shedding some down (i.e. losing feathers) through the shell. The 7D shell is also incredibly thin and you’ll need to be careful with the bag if you want it to remain down-filled and hole-free.
The Price: The Zpacks Mummy Sleeping Bag isn’t the least expensive option available, but it also isn’t the most expensive. For an ultralight bag using 900-fill power down, the price tag is about what you would expect. It’s certainly not cheap and with nowhere to test it out before ordering it can be a bit intimidating. Fortunately, shipping is free and Zpakcs accepts returns of new/unused gear within 30 days. That said, customers are responsible for return shipping.
The Zipper: The zipper on the works okay but you aren’t going to be completely free from snags unless you’re careful. So long as you keep your finger in the channel behind the zipper while zipping and unzipping – and you move slowly – the zipper works just fine. When I’m outside the bag, I have no issues zipping and unzipping it – even quickly. However, when I am inside the bag, I often get the zipper snagged – which is dangerous with such a delicate shell. There is a zipper guard to prevent snags on the draft tube and shell, but it’s only somewhat effective.
The Hood: The hood on the Zpacks Mummy Sleeping Bag doesn’t inspire much confidence when you first look at it. It lies seemingly flat against the ground and there isn’t anything giving it structure around the hood’s perimeter. It operates more like a down-filled ground sheet for your head than an insulating hood when it’s not cinched. It’s also worth pointing out there is no draft collar. This is a piece of fabric and/or baffle to prevent your warm, body-heated air from escaping from the top of your bag (i.e. where your head pokes out). If you cinch the hood up around your head, it can come down fairly tight and prevent drafts, but if you’re like me, the mega-cinch is typically reserved for only the coldest of nights.
The Options: If you’ve read all my reviews you’ll notice that this review is quite similar to my Zpacks Zip Around Sleeping Bag review. That’s because the Zpacks Mummy Sleeping Bag is the same bag except that it has a hood. The line between “new product” and “product options” is oftentimes a tricky one for companies. Should Zpacks offer just a single sleeping bag product that comes with an optional zip-around zipper and/or a hood? Maybe. But that’s not for me to say. I’m just here to let you know that these are the same bag except one has a hood.
The Color: The Zpacks Mummy Sleeping Bag comes in four colors, black, blue, green, and orange. I went with the green because it looks nice on the Zpacks product page, but the actual color of the sleeping bag isn’t all that great. It’s more a sickly pale green than a more solid bright green. This is likely due to the bag’s nylon shell being incredibly thin and the bag itself being a bit difficult to photograph (you can see in the photo gallery above that the bag does not always appear to be the same color). Not a huge deal, but something to note when you’re spending this much on a sleeping bag.
The Storage Bag: You get a great stuff sack with the Zpacks Mummy Sleeping Bag, but you don’t get a storage bag. I suppose you could always just use a garbage bag for this, but it’s still nice to have a nice cloth storage bag for your sleeping bag(s) and/or quit(s). PSA in case you were unaware: do not store your sleeping bags compressed or in stuff sacks – this can (and will) damage the down.
Who is it for?
The Zpacks Mummy Sleeping Bag is a versatile option for anyone prioritizing weight and in need of a hood. That said, these two ideas are a bit at odds with one another. Since this bag can also be laid flat, it might be a good (albeit expensive) transition between traditional mummy bags and quilts.
- Beginner Backpackers: I would probably not recommend this as your first sleeping bag if you haven’t spent too much time sleeping in feather-filled nylon sacks.
- Weekend Warriors: This would be a good fit if you’re looking for a single bag to facilitate changing environments throughout the year – even (potentially) more so than the hoodless version.
- Thru-Hikers: The target market for this bag. If weight is of the utmost importance and you must have a hooded bag, this bag is worth checking out.
|Big Agnes Torchlight 20||$320||43 oz / 1.219 kg||20°F / -6°C||600 goose||19 oz / 538 g|
|Feathered Friends Egret UL||$549||27.2 oz / 771 g||20°F / -6°C||950 goose||17.3 oz / 491 g|
|Feathered Friends Swallow UL||$589||31 oz / 879 g||20°F / -6°C||950 goose||16.8 oz / 476 g|
|Marmot Bantamweight 15||$589||24.3 oz / 689 g||15°F / -9°C||900 goose||N/A|
|Mountain Hardwear Phantom 15||$550||33.2 oz / 941 g||15°F / -9°C||850 goose||N/A|
|Rab Mythic Ultra 360||$650||21 oz / 606 g||20°F / -6°C||900 goose||N/A|
|REI Co-op Magma||$399||28.2 oz / 799 g||16°F / -9°C||850 goose||15.9 oz / 451 g|
|Sea to Summit Spark Ultralight||$489||23.5 oz / 667 g||18ºF / -8ºC||850 goose||15.2 oz / 431 g|
|Therm-a-Rest Hyperion 20||$500||20 oz / 567 g||20°F / -6°C||900 goose||12.5 oz / 354 g|
|Therm-a-Rest Ohm 20||$460||22 oz / 624 g||20°F / -6°C||900 goose||12.5 oz / 354 g|
|Western Mountaineering UltraLite||$580||30 oz / 850 g||20°F / -6°C||850 goose||16 oz / 454 g|
|Western Mountaineering Versalite||$655||32 oz / 907 g||10°F / -12°C||850 goose||20 oz / 565 g|
|Zpacks Classic||$449||18.8 oz / 533 g||20°F / -6°C||900 goose||13.7 oz / 388 g|
|Zpacks Full Zip||$479||21 oz / 595 g||20°F / -6°C||900 goose||13.7 oz / 388 g|
|Zpacks Mummy||$539||23.2 oz / 659 g||20°F / -6°C||900 goose||15.6 oz / 442 g|
|Zpacks Zip Around||$479||21.6 oz / 612 g||20°F / -6°C||900 goose||14.5 oz / 412 g|
It’s a strange dilemma because if you’re looking at this bag you presumably want something as light as possible. The hood adds weight and when you look at the added performance over the but the added weight of the hood comes as questionable performance. It may be a better bet to go with the Full Zip and then invest that extra weight in something more versatile like a beanie/buff/balaclava to keep your head warm instead.
Rating + Recommendation
If weight is of the utmost importance and you definitely need a hood on your sleeping bag (that you’re looking to cinch up at night), the Zpacks Mummy Sleeping Bag may be worth checking out. If you’re new to backpacking, are looking for something a bit more durable, or need a hood with some structure that doesn’t need to be cinched, it may not be the right choice for you.
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