Long-term review: Osprey Aether/Ariel Pro 70 || Tough mid-weight load-hauler

The Osprey Aether Pro weighs less than 4 pounds but has the weight and load-carrying capacity of a pack that normally weighs 5 to 7 pounds. It’s become my go-to for guiding, big game hunting, and spousal trips.

Recently I had to look through photos of the Great Western Loop from 2007. My, my, I had such a small and light pack. But the trend has been moving in the wrong direction ever since, and for about a year I’ve been using a pack that has more volume and weighs more than anything I’ve used since 2002, when I started the Appalachian Trail as a noob with a Mountainsmith Frostfire 4500.

I have now used the Osprey Aether Pro 70  for about 50 days, including on most of my guided trips for the past year, a spousal trip to Utah’s Cedar Mesa, an elk hunting trip in the Colorado Rockies in November, and weighted training hikes in Boulder’s foothills.

For women, Osprey offers the Ariel Pro 65, which has identical features and materials, but a women-specific fit and five liters less capacity. Nearly all of my comments about the Aether are applicable to the Ariel as well.

Long-term review: Osprey Aether Pro 70 and Ariel Pro 65

The Osprey Aether/Ariel Pro will appeal most to backpackers who:

  • Must carry large or heavy loads that exceed the volume or load-carrying capacity of modern lightweight packs; but,
  • Want this performance from a pack that weighs 3 to 4 pounds, rather than the normal 5 to 7 pounds.

When I’m leading clients, hauling out elk quarters, or carrying most/all of the food and gear on a group trip, the Aether Pro has become my go-to. I think Osprey also imagined it being used for alpine/mountaineering expeditions and for adventurous long-distance hikes (e.g. thru-hiking the Brooks Range).

My sole criticism of the Aether/Ariel Pro is its external storage. Instead of the removable compartments located in the “wedge” between the hipbelt and main compartment, I’d rather have conventional side pockets and hipbelt pockets, plus a shoulder strap pocket. But I’ve overlooked this shortcoming because of its performance otherwise.

Spousal trip in Utah’s Cedar Mesa, when I carried just about everything for the two of us (plus a lot more, it seemed).

Key specs

  • Volume: 70 liters (4272 cubic inches) in size Medium
  • Strong and durable fabrics throughout
  • Stiff aluminum peripheral frame and a single aluminum center stay
  • Mesh-covered aerated foam back panel
  • Heat-moldable foam hipbelt
  • Two front compression/attachment straps
  • Attachment points for trekking poles, two ice tools, hydration reservoir, and sleeping pad
  • $375 MSRP
  • More information (men’s, women’s)

The spec weight of the Aether Pro (in size Medium) is 3.94 pounds (3 lbs 15 oz, 1.79 kg). My pack is over-spec by 2.9 oz; it weighs 4 lbs 1.9 oz (1.87 kg). Its weight can be further reduced by removing features:

  • Floating top lid (5.1 oz)
  • Two side compression straps (0.5 oz each, or 1.0 oz total)
  • Zippered side pocket (2.7 oz)
  • Cinch-able side pocket (2.6 oz)

The total weight of these removable items is 11.4 oz, which would reduce the spec pack weight to 3 lbs 3.6 oz, but at the cost of some functionality.


To help you decide if the Aether/Ariel Pro is right for you, comparing it to other packs is probably useful.

Aether Pro vs Aether AG

The Aether/Ariel Pro was new for spring 2018, and Osprey kindly sent me it and two other packs that it had updated or launched that season, the Exos and Levity. The Pro is essentially a stripped down version of the Aether AG (“Anti-Gravity”).

Compared to the AG, the Pro:

  • Uses more premium fabrics;
  • Has a simpler harness system that’s lighter and probably carries better, but less ventilated;
  • Is 1.3 pounds lighter, with an opportunity to shed extra weight by removing features; and,
  • Costs $65 more, $375 vs $310 for the 70-liter versions.

The only thing I wish the Pro had is the AG’s external pockets.

Aether Pro vs “sweet spot” packs

My pack recommendation for most backpackers is a 2.5-pound framed pack that is nicely featured, made of durable materials, and costs $200-$300 such as the Osprey Exos, Sierra Designs Flex Capacitor, and ULA Circuit.

Such models are ideal for standard thru-hikes and high routes, and for backcountry trips up to 7 or 10 days. If your plans are more exceptional and require a pack with more volume or greater load carrying capabilities, plus some additional durability, the Aether/Ariel is worth a look.

Aether Pro vs. Deuter, Gregory, and Mystery Ranch

Other packs match (and may exceed) the volume and load-carrying capacity of the Aether Pro, including the Gregory Denali 75, Deuter Aircontact 65 + 10, and Mystery Ranch Glacier. But none of them rival its sub-4 pound weight. In size Medium, the Denali weighs 6 lbs 3 oz; the Aircontact, 5 lbs 6 oz; the Glacier, 5 lbs 10 oz.

Aether Pro vs Seek Outside Divide and Unaweep

The most direct comparisons to the Osprey Aether/Ariel Pro may come from the backpack hunting industry, which is presented with similar volume/load demands. I’m specifically thinking of the Divide 4500 and Unaweep 4800 from Seek Outside. Both packs weigh in the low- to mid-3 pounds and approach $400.

This pack display from a guided trip in Rocky Mountain National Park puts the Osprey Aether Pro in perfect context. On left, I’m carrying it. But clients have the Flex Capacitor, MTC Jam and Osprey Levity. Note: All our packs are near empty in this photo, since we did a day-hike from a base camp on Day 2 to help acclimatize. Credit: Andrew Manalo.

Suspension + harness

The standout feature of the Aether/Ariel is its suspension. Simply put, this pack is designed to haul weight. It’s light-years better than the Exos, and even in a different league than the Flex Capacitor, which is considered to carry weight better than most (all?) sub-3 pound packs.

The peripheral frame made of 7075 tubular aluminum is extremely stiff, so it efficiently transfers weight. As I’ve come to expect of Osprey, the harness system is masterfully fitted, and the weight is distributed well across the hipbelt, shoulder straps, and back pancel, which have generous but firm cushioning.

On overnight trips I regularly have carried loads in the low-40’s, and on recent training hikes I’ve carried exactly 50 pounds (courtesy of two 12″ x 12″ concrete stepping stones wrapped in old towels, plus some other gear for filler). I will never say that carrying 50 pounds is comfortable, but some packs do it more gracefully than others, and the Aether/Ariel is among them.

On a recent training hike in Boulder’s foothills, wearing the Black Diamond Rhythm Tee and carrying the Osprey Aether Pro 70 pack, loaded with 50 pounds.

To achieve this load-carrying performance in a sub-4 pound pack, Osprey gave the Aether Pro a more conventional back panel, abandoning the ventilated trampoline that you’ll find on the Exos and Aether AG. The mesh-covered aerated foam (branded as AirScape) provides relatively little ventilation in reality, so you should expect perspiration to buildup on warm days and during hard efforts.

The aerated back panel does little to reduce perspiration build-up in warmer conditions and during hard efforts, as evidenced by the sweat line. But a more ventilated back panel would add weight and expense, and compromise the load stability.


The Aether Pro is spec’d with four types of fabrics:

  • Main body: 210d nylon x 200d UHMWPE
  • Bottom: 200d UHMWPE
  • Accent: 315hd oxford
  • Trim: not specified, but appears to be a 200d-ish nylon

UHMWPE stands for ultra-high-molecular-weight polyethylene, and is the source material for Dyneema and Spectra fibers. Presumably as a cost-savings measure, Osprey chose non-branded UHMWPE fabrics. Sierra Designs made the same decision with the Flex Capacitor, and internally we referred referred to the fabric as “Chineema.” Osprey has branded the body fabric as NanoFly.

The bottom fabric is a pure UHMWPE.

While writing this review I inspected my pack for wear, and found no abrasions or tears. The Aether/Ariel seems like it’s built for a lifetime of use. If this proves not the case, it’s covered under Osprey’s All Mighty Guarantee.

The four fabrics: 210×200 gridstop body, 200d Chineema bottom, 315d Oxford accent, and an unspecified 200d-ish trim.


The main compartment is tall and narrow, even before the extension collar is utilized. I believe this shape leads to better load stability, but it’s disappointing that a full-sized bear canister (e.g. BV500) cannot be stored horizontally in the Aether. Shelters and hammocks without intentionally short pole sets will have to be placed vertically, too.

External storage

The floating top lid is nicely sized, and is convenient storage for items that you occasionally need during the day, such as toiletries, snacks, extra water storage, and even a windshirt or minimalist rain jacket. If you don’t need its volume or wish to pare 5 oz from the Aether, it can be easily removed.

The hipbelt/side pockets are underwhelming, and I consider them to be the Aether’s most notable imperfection. I believe it’s essential to have quick access to oft-needed items like water, a camera or phone, maps, skin treatments (e.g. lip balm, sunscreen, insect repellent), a headnet, water purification and other items. The design of hipbelt pockets and side pockets is vitally important — they must be accessible, secure, and generous.

To their credit, the hipbelt/side pockets are easily accessible, and one can be zippered shut. But their total volume is marginally acceptable, and the cinch-able pocket is deep enough only for a 1-liter Nalgene. Using a 1-liter Smartwater bottle (which weighs 2.4 oz less) is impractical — it immediately slips out if you lean forward, like to pick up a trekking pole or step under a downed tree.

I appreciate that Osprey tried something different here, but personally I would have preferred the Aether AG design, which includes two permanent side pockets and two permanent hipbelt pockets.

Only a 1-liter Nalgene can be used with the cinch-able side pocket. A 1-liter Smartwater bottle slips out easily.

Compression and utility

The Aether/Ariel Pro has two sets of compression straps:

  • Two horizontal straps across the front, and
  • One Z-style removable strap on each side

In addition to stabilizing the load, these straps are useful for securing trekking poles, an umbrella, ice tools, and long tent poles. I have not tried, but I’m certain that snowshoes would fit perfectly on the front. Skis could be attached, too, but I’d want to protect the pack fabric from the metal edges first.

The side compression straps photograph well, but the webbing does not slide easily through the rectangular sliders. O-rings would have been a better choice.

External attachments and utility is mostly excellent. I would only recommend that the hardware on the removeable side straps be changed to an O-ring, to improve glide.

Questions about the Aether/Ariel Pro 70, or have an experience with it? Leave a comment.

Disclosure. I strive to offer field-tested and trustworthy information, insights, and advice. I have no financial affiliations with or interests in any brands or products, and I do not publish sponsored content

This website is supported by affiliate marketing, whereby for referral traffic I receive a small commission from select vendors like Amazon or REI, at no cost to the reader. As an Amazon Associate I earn from qualifying purchases.

Posted in , on May 21, 2019


  1. Josh Wood on May 22, 2019 at 5:15 pm

    Thank you for this review! Myself and a few other guides here in Tasmania have been very interested in this pack and there hasn’t been many relevant reviews of it.

    • CG on August 25, 2020 at 2:50 am

      Mr. Skurka.
      Enjoyed the review man. Practical. Unbiased. Clean. You should mention though that this pack is very, very easy on the eye. Butterflies in the tum-tum easy.

      (from Africa)

  2. Adrian on May 29, 2019 at 4:56 am

    I really enjoyed my Aether as well for heavy loads. Although it was nowhere near looking like I would ever wear it out, I found a way to swap it out for a Seek Outside Divide. The Aether was never uncomfortable, but I have to say the Seek Outside harness lives up to it’s reputation, and is a step up again. For wet conditions I also enjoy the roll top and fabrics that don’t soak up water, Osprey’s fabrics do get a bit saggy and heavy when wet.

  3. Loco Raindrops on July 4, 2019 at 9:07 pm

    Its primarily designed as an alpine climbing pack so that is why there are a lack of side pockets.

    Look at the HMG Ice Pack. Same general concept. Different execution.

    It can be stripped to he a bare bones climbing pack. If you want a pack fir trails then buy the AG or standard Aether.

    I hate when folks review gear and bitch when it doesnt perform in a realm for which it was really intended.

    You think its designed as a mountaineering pack?

    Maybe you should take 5 minutes to call Osprey and ask.

    If you want a hunting pack buy a Kifaru.

    I really wish ur dumb shit wouldnt hit my feeds because while you may have travelled and have experience truth be told you dont know your ass from a hole in the ground.

    The more I read your reviews the more I realize this.

    There are no side pockets because if you are climbing and say put a nalgene in the side pocket it could possibly come out and take out someone on a rope team below you.

    • Andrew Skurka on July 5, 2019 at 10:00 am

      Yes, let’s ask Osprey for what purpose the Aether Pro was designed. Per its website:

      “Osprey’s stripped down, streamlined and svelte Aether Pro 70 is made for type-two adventures that span days or months; alpine climbing expeditions with remote basecamps, or boundary-pushing thru-hikes through unknown landscapes where the only trail is the one you make.”

      And of the Aether AG, on which the Pro is entirely based, it says: “For backpacking, thru-hikes and alpine expeditions, the Aether AG Series has a pedigree like no other pack.”

      In light of this, I double-down on the Aether Pro needing better side and hipbelt pockets.

      • Loco Raindrops on July 5, 2019 at 10:13 am

        The pack was designed based on feedback of guides.

        Tell me.

        How many guides lead backpacking trips? I never knew guiding trips on amy if the 3 long trails was a thing.

        If you need a guide to put one foot on front of the other on a maintained trail chances are you shouldnt leave your home.

        Also if you look at Ospreys vid of the pack you can see it being utilized by alpine guides.


    • Rodney on September 2, 2019 at 11:37 pm

      Man, you’re nasty…

  4. Loco Raindrops on July 5, 2019 at 10:15 am

    They state that it can be used for backpacking skmply because rhey want to make money and not limit their market.

    You if anyone should know this.

  5. Shane on July 26, 2019 at 9:05 am

    Alirghty then, Loco raindrops is entirely loco.

    Good review, thank you. I’m looking for a new hunting pack and not a big fan of Mystery Ranch/Kifaru/etc and this is helpful. I’ve used a old osprey argos 85 for alot of years, and its packed out a bunch of animals but coming in around 7 pounds, it is bulky.

    How relfective is the material on the pack? Is the grey real shiney? I was looking at the non-pro model because it comes in the drab green but this review might make me reconsider.

    Just recently found your site, thanks for all the good work.

    • Andrew Skurka on July 29, 2019 at 8:32 am

      There is no reflective material on the pack. The gray/white body fabric is probably not ideal for hunting, but neither is 500 square inches of fluorescent fabric (required minimum in Colorado, and probably many other states too). I’ve yet to feel like the color or pattern (i.e. non-camo) made the difference in a hunt, although YMMV if you’re a more experienced hunter and using something more intimate than a rifle.

    • Loco Raindrops on August 15, 2019 at 11:08 pm

      Not Loco at all. Been using osprey packs longer than most of you been breathing so I contacted a brand rep I know and yes the pack was designed to be more focused towards mountaineering.

      So yeah..

      Of course they are not going to limit themselges in the market and say its only for mountaineering.

      Most of you including Skurka doesnt now your ass from a hole in the ground.

      You ul folks are funny.

      Same people who scream light is right are dumping your trail runmer in landfills every 1 or 2 season.

      Guess LNT only applies when its not an area you have to look at.

      • Andrew Skurka on August 16, 2019 at 7:37 am

        You’ve stated your opinion, thank you. But you’re no longer welcome here. Please find another site to troll.

      • Derek on February 23, 2020 at 5:59 am

        I have the Osprey Aether AG 70, and there’s some things I don’t like about it, but I adapt and change it depending on objective. Right now my objective is trainhopping across America, and the pack is holding up nicely. Next month I’ll reconfigure it for Yosemite. Loco Braindrops sounds like you need to go on a hike to quiet that extra voice in your head that’s making up all kinds of fantasy scenarios about complete strangers you know nothing about, and probably even less about backpacking lol, good luck!

  6. Bret on August 28, 2019 at 7:44 pm

    Andrew, have you hauled out meat in this pack? What is your estimated upper weight limit for this pack? I’m looking for a load hauler for hiking with kids, and I like the idea of being able to use my backpacking pack for hunting instead of my old external freighter frame.

    • Andrew Skurka on August 28, 2019 at 8:36 pm

      No, not yet. Hoped to in November 2018, and hoping to this October.

      I think your legs and back will break before the pack will. I’ve carried out an elk twice in a Flex Capacitor (50 to 70 pounds per load, two loads per animal), and the Aether Pro has substantially more weight capacity than that. I think my body would refuse the weight before the pack will.

      I’m less convinced that the pack is a good family hauler, because it’s just not that big. If you are talking about carrying a couple of sleeping bags, a big tent, a big stove, and all the food, I think you probably want something more like a 100-liter pack than a 70L. Doesn’t seem like a big difference, but that’s the volume of another weekend pack.

  7. Marimac on July 2, 2020 at 1:53 pm

    A great review and just the type of info I was looking for.
    Thanks for sharing your hard-earned experience.
    I have the Aether AG 70 and am happy with it for CDT sections and multiple Grand Canyon trips.

  8. Pete on July 23, 2020 at 9:03 am

    Thank you, Andrew, for the great review. I have been searching for a lightweight hunting pack capable and comfortable for loads over 50 lbs. I am currently using an REI Flash 67 which is terribly uncomfortable over 30 lbs and was horrible for hauling out a black tail and gear last year. I appreciate most of the reviews as well. I am also looking at the Seek Outside Divide and Unaweep as alternatives. They have great reviews but certainly cost more than the Aether Pro once you add the additional modular features. And to get a hydration port in a larger model (not the Gila) you have to order a custom pack. Also not sure what I’ve read about the wide SO shoulder harnesses widths. Are the Seek Outside packs worth the money? Would I be just fine with a Sierra Designs Flex Capacitor?

    • Andrew Skurka on July 24, 2020 at 10:09 pm

      The Flex works as a backpacking pack that you can occasionally extend into the hunting season, but I wouldn’t consider it a hunting pack.

      I have the SO Divide but have not used it enough to compare it to the Aether Pro — I’m not complaining about filling my tag on the first day, but it’s not good for product reviews.

  9. Eli on June 3, 2021 at 5:57 pm

    Just one note: I can fit a BV500 horizontally in mine— granted, it’s a tight fit, and due to the taper of the pack the lowest part of the canister can only go as low as the midpoint of the frame. I’m not sure if that’s a matter of sizing (I have a large) or if Osprey has made some minor updates since you got yours (I just picked mine up this winter).

  10. Mark on June 7, 2021 at 4:37 pm

    Thanks for the review, Ive spent a few hours hunting for reviews of the pack especially for mountaineering/backcountty ski usage and it’s quite hard to come by, but your review is quite useful in its own way, thankyou. Shame some people have a chip on their shoulder and publicly take out their personal issues so unneccrssairily , pretty disappointing. Could I ask as this hasn’t been made clear in reviews do far whether the padded hip belt (not the add on pockets) is easily? removable to further strip down the pack for summit climbs (the padded belt would get in the way of a climbing harness). I usually like to know how overloadable climbing packs are. Is the pack limited to 70 litres or can the extension extend the volume and by how much? Thanks very much in advance from Melbourne, Australia

    • Andrew Skurka on June 7, 2021 at 4:53 pm

      The hipbelt is not terribly thick, and if you started cutting into it I think there’s a chance that you could regret the mess and that you might find that the exterior fabrics, padding, and stiffening materials (plastic probably) are all glued or sewed together.

      70 liters seems to be about the max volume of the pack.

      • Mark on June 7, 2021 at 7:11 pm

        Thanks again. Not wanting to cut into it, just remove it from the pack body temporarily for technical summit climbs where it would be unnecessary.
        I actually found the PDF manual for the pack, wow first time I’ve ever seen one LOL. I went through it and Osprey gave some simple instructions on how to remove it, doesn’t seem so onerous, which was the one major feature that I was concerned about. Looks like the harness and hip belt are replaceable which is a bonus. The more i read about it the better it looks.
        Once we get out of our current lockdowns I’ll head over to a store for a look see.

        • Mike on March 14, 2022 at 9:43 am

          Can you share a link to the pdf? I have also have this pack and love it.

          • Mark on March 14, 2022 at 8:12 pm

            It’s on my Google drive
            Hopefully that works. Taken it on a few test runs, hip belt comes off without too much hassle, and it’s great that I can strip it down do it’s not not too bad, narrower than what I thought it would be in practice so I struggle to pack it on the big trips, but very very comfortable with very heavy loads. Only issue was that I probably should have taken the slightly smaller pack size as the frame interferes with my helmet whilst looking upwards, but I didn’t think of taking my helmet along when I was fitting the pack lol.

  11. Lee on October 7, 2021 at 5:44 am

    Thank you for the review, and complete weight breakdown, something I couldn’t find anywhere else of the internet, including Osprey official site.

    P.S that 1 guy is a prat, you gave a great review.

  12. Albert on March 14, 2022 at 8:49 am

    Mr. Skurka thank you for the review, it is really appreciated! I have had my eye on this pack for a long time, it has all of the features that I want and none that I dont want. As far as I know this pack was launched in 2018. The newest version of the Aether was launched in 2020 and there hasn’t been a new Aether Pro released up until now. Do you have any information if there is a new Aether Pro on the horizon? The reason I am asking I would rather wait a few months if the new version is on its way.

    • Andrew Skurka on March 14, 2022 at 3:54 pm

      I’ve not heard about a new Aether Pro, one way or the other.

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