Osprey Exos Pro 55 & Eja Pro 55 Backpack Review

osprey eja pro ultralight backpack

Big weight savings upgrade for a beloved backpacking pack. Comfiest in weight class!

Brand new and exciting for 2023, the Osprey M’s Exos Pro 55 & W’s Eja Pro 55 ultralight backpacks are slimmed down versions of their forebears, the original M’s Exos 58 and W’s Eja 58. The Pro models are offered in addition to the originals, and combine ultralight materials and a slightly smaller chassis to achieve nearly a full pound of weight savings – 33 oz vs 47 oz.

At just under three pounds, the original Exos and Eja were a bit too heavy to be considered ultralight backpacks, but at just over two pounds, the Osprey Exos Pro 55 & Eja Pro 55 hit the ultralight backpack bullseye.

  • Weight:  33.2 oz
  • Price: $290
  • Materials: 100D recycled nylon ripstop with DWR
  • Frame: 3.5mm alloy peripheral frame with adjustable suspension and tensioned mesh back panel
  • Load Capacity: 30 lbs
  • Internal Volume: 46
  • External Volume: 9L lid + pockets
  • Pros: Comfiest in weight class. Ultralight. Recycled materials. Good back aeration and load transfer.
  • Cons: Slightly delicate. Smaller pockets. Lower load capacity. Some users found original versions rubbed hips/upper glutes.


As ultralight backpacks go, the Osprey Exos Pro 55 & Eja Pro 55 are about as fully-featured as one can hope for. The aeriated foam shoulder and hip belt connect to an adjustable external frame system that transfers weight very comfortably and lifts the back panel off the back with a taught mesh surface for maximum ventilation.

It also features a full sized, detachable lid with 9L of storage, two hip belt pockets, and three mesh pockets spanning the sides and back.

Difference between pro and original models

Very few differences in features between original and pro are perceptible, but we’ll call out what can. First, the rear external pocket is now mostly nylon, with mesh used only for stretch paneling. This is definitely an upgrade as these packs were known to get mesh rips.

In totality, there also appears to be fewer external straps and cinching doodads. The hardware like clasps and buckles got smaller, and might be a bit fiddly. We don’t think dinky buckles are the best way to save weight.

But as the overall design is basically the same, the Pro models derive most of their weight savings from material upgrades. Comparing listing, that translates to slimmer frame architecture by way of 3.5 alloy rods, instead of 4mm.

We presume this is why the load capacity is rated to 30 down from 35. The Pro’s also use “NanoFly™: 100D Nylon x 200D UHMWPE ripstop” compared to the originals which are sewn with “bluesign® approved recycled 100D high tenacity nylon ripstop.”

As Osprey has not provided additional fabric performance info, we’re left to assume that the new material is lighter and has a superior durability-to-weight, but that the older material is heavier but still has a better total durability, and is also more eco-friendly. Lastly, we’ll note that Pro models cost only $30 more than the originals, which is an incredibly good deal for nearly a pound of weight savings.


This backpacking backpack is brand new and we’ll be testing it more thoroughly this season. We’ll report back on how it does once that gets underway. One thing we’ll look for is how the bottom of the frame interacts with upper glutes/hips, as this has been known to rub on a select few users.

But in conclusion, this is an an exciting ultralight backpack with excellent stats, and if the Osprey Exos Pro 55 & Eja Pro 55 hold up in the backcountry, they’re in for some very high praise. Speculatively, this could be the best all time ultralight backpack from a mainstream outdoor brand.

Compare this to more great options in our guide to the best ultralight backpacking backpacks of the year.

osprey exos pro 55 backside side angle
osprey exos pro 55 front side


This post contains affiliate links. If you make a purchase after clicking a link on this site, a small portion of the sale helps to support us at no additional cost. We are never paid  directly to write about a product, nor are we ever required or obliged to do so. Finally, this post expresses our own independent opinions and does not represent the views of any brand we cover.