Osprey Exos 48 review: the accessible way into lightweight backpacking

The Osprey Exos 48 is the pack that gets most UK hikers into lightweight backpacking without asking them to gamble on an imported cottage brand or a stripped-out frameless sack. It weighs a fraction over 1.1kg, it has a proper suspended mesh back that keeps air moving on a climb, and it carries a real multi-day load in a way that the true featherweight packs simply cannot. That combination is why it is Amazon's Choice in its category, holds a 4.7-star average across several hundred UK ratings, and remains the default recommendation whenever someone asks how to shave weight off a heavy expedition rucksack without regretting it.

It is not the lightest 48-litre pack you can buy, and it is not trying to be. Osprey has built a lightweight pack rather than an ultralight one, and the difference is the whole point of this review. What you get for the extra couple of hundred grams over a cottage build is ventilation, a frame that transfers weight to your hips, mainstream availability and Osprey's warranty. What you give up is the last slice of weight saving and some of the load ceiling a bigger pack offers. For the hiker moving from a 2kg-plus rucksack towards a lighter setup, that is close to the ideal trade. Here is the full picture.

Who the Exos 48 is for

The Exos 48 suits the hiker who wants to go lighter without going extreme. If you have done a few multi-day walks with a heavy 60-litre pack, learned what you actually carry, and now want to drop weight off your shoulders, this is the natural next pack. Forty-eight litres is enough for a three-season UK kit including a tent, sleeping bag, mat, cooking gear, insulation and a couple of days of food, provided your kit list is disciplined rather than sprawling.

It also suits anyone who is nervous about buying light gear. The cottage ultralight world is full of superb packs, but most of them are ordered direct, shipped from abroad, and impossible to try on before you commit. The Exos removes all of that friction. It is stocked on Amazon UK, in Blacks and across the outdoor trade, it comes in defined sizes you can fit properly, and if something fails it is covered by Osprey's All Mighty Guarantee. For a first serious step into lightweight backpacking, that safety net matters.

Who should look elsewhere? Two groups. First, the weight purist chasing a sub-4.5kg base weight, who will find the Exos heavier than a Zpacks or Hyperlite build and will happily pay in comfort and price to save the grams. Second, the hiker who habitually carries big, heavy loads, winter kit, a bulky tent, a week of food, for whom a fully framed 60-litre pack like the Osprey Talon 33's larger siblings or a traditional expedition sack will carry heavy weight more happily than any lightweight pack can.

The AirSpeed suspended mesh back

The feature that defines the Exos, and the reason it carries far better than its weight suggests, is the AirSpeed suspension. It is a tensioned trampoline-style mesh panel stretched across a peripheral frame, and it holds the body of the pack roughly a finger's width off your back. Air moves through that gap. On a hot, sweaty climb, the kind of ascent that leaves a soaked patch down your spine with a flat-backed pack, the Exos keeps far more air flowing against your shirt.

This is not a gimmick and it is rare at this weight. Most lightweight and ultralight packs use a simple foam back panel pressed flat against you, because a tensioned mesh system costs both grams and complexity. Osprey has managed to build one into a pack that still comes in comfortably under 1.2kg, and that is the single thing that sets the Exos apart from the frameless and lightly framed competition. In warm British summer conditions, or on a long humid day in the Brecon Beacons, the ventilation is worth the small weight penalty on its own.

The suspended design does have one consequence worth understanding. Because the load sits slightly away from your back rather than hugged tight against it, the pack's centre of gravity is a fraction further out than a body-hugging ultralight sack. On steep, technical scrambling ground that can feel marginally less stable, though for the walking and easy scrambling most UK backpackers do it is a non-issue and the airflow easily wins the trade.

Weight: sub-1.2kg for a framed pack

The men's Exos 48 weighs around 1.16kg in the smaller size, rising to roughly 1.18kg in the largest, with the full floating lid fitted. That is the number to keep in perspective. Against a traditional 48 to 55-litre backpacking pack, which routinely weighs 1.8 to 2.3kg, the Exos saves the better part of a kilo before you have packed a single item. Against a true cottage ultralight pack, which can dip under 900g or even below 600g, the Exos is the heavyweight of the lightweight class.

Both comparisons are fair, and both matter. Coming down from a heavy pack, the Exos feels transformative. Coming across from a Durston or an Atom Packs build, it feels like the sensible, robust option that traded a little weight for a frame and a warranty. The pack also lets you claw some of that weight back: the floating lid is fully removable, and stripping it drops the pack towards 1kg while a built-in FlapJacket flap keeps the top of the main compartment covered. For a fast, light overnighter that is a useful option to have.

Load carry: how much can it take?

This is where a lightweight pack lives or dies, and the Exos does well within honest limits. The peripheral aluminium frame, the tensioned back and a genuinely supportive hip belt let it transfer weight onto your hips rather than hanging it off your shoulders, which is exactly what the frameless ultralight packs struggle to do once the load climbs.

Osprey rates the pack for loads up to around 18kg, and independent testers consistently report it staying comfortable up to roughly 16kg, with the best carry experience in the 11 to 16kg window. That is not a coincidence, it is the sweet spot the whole design targets. Load it beyond about 16kg and the light hip belt and slim frame start to show their limits, the belt padding is thinner than a traditional pack's and the load transfer begins to soften. Under about 8kg, some testers note the reverse, that the structured frame carries a very light load slightly less sweetly than a soft frameless pack that moulds to a small load.

The practical reading is simple. The Exos is at its best carrying a realistic three-season UK backpacking load, which is precisely the weight most people going lightweight will actually be carrying. Match your loaded weight to that window and it carries beautifully. Try to make it a heavy-haul expedition pack and you have bought the wrong tool.

How it copes with a UK multi-day kit

UK conditions ask more of a lightweight pack than the dry American trails these packs are often designed around. Our weather forces a proper waterproof shell, warmer insulation, a shelter that copes with wind and sideways rain, and usually a bit more spare clothing. A sensible, comfortable three-season UK base weight for a fit hiker lands around 7 to 9kg, and once you add a couple of days of food and water you are carrying 11 to 14kg. That figure sits right in the middle of the Exos's happy load range, which is the strongest single argument for this pack over a lighter one.

Forty-eight litres is enough volume for that kit if you pack with discipline. A compact three-season tent, a quilt or light sleeping bag, an inflatable mat, a stove and pot, insulation, waterproofs and food will fit, with the large stretch front pocket swallowing a wet shell so it never soaks the rest of your gear. Where it gets tight is winter, a bulkier four-season sleeping bag, or the hiker who has not yet trimmed their kit list. If that is you, look at a 55 to 58-litre pack instead.

One important caveat for British weather: the Exos does not come with a rain cover, and its light nylon body is water-resistant rather than waterproof. The correct approach, and the one every experienced lightweight hiker uses, is a pack liner. A single dry bag or roll-top liner inside the main compartment keeps your sleeping bag and insulation bone dry regardless of how wet the pack fabric gets, which is lighter and more reliable than a flapping external cover. Pack the things that must stay dry inside the liner and stop worrying about the rain.

Fit and sizing

The current Exos 48 comes in two frame sizes, S/M and L/XL, each with a ladder adjustment system that gives up to around 10cm of torso length adjustment. That is a meaningful improvement on older fixed-size Osprey packs, because it lets you dial the harness to your back length rather than hoping an off-the-peg length happens to suit you. Getting that adjustment right is the difference between the load sitting on your hips and it dragging on your shoulders, so it is worth spending time on before the first long walk.

The hip belt and harness are lighter and slimmer than Osprey's heavier packs, in keeping with the pack's purpose. They are comfortable within the load range the pack is built for, but they are not the deep, heavily padded belt of an expedition sack. That is a deliberate weight saving rather than a flaw. As with any pack carrying real weight, fit it loaded, in a shop if you can, and check the belt wraps your hip bones properly and the harness has no gap at the shoulders.

Organisation and features

The Exos keeps its feature set lean but usable, which is the right instinct for a lightweight pack. The layout is clean rather than clever, and everything on it earns its weight.

Front stretch mesh pocket. A large external shove-it pocket across the front takes a wet waterproof, a damp fly sheet or anything you want to grab without opening the main compartment. On a wet British walk this is one of the most-used features on the pack.

Twin side pockets. Deep stretch mesh side pockets hold water bottles and are angled so you can reach a bottle without removing the pack. They also take tent poles or a folded walking pole securely.

Hip belt pockets. Two zipped hip belt pockets sit within reach for snacks, a phone or a compass. The current generation uses tougher woven fabric than the fragile stretch mesh of older models.

Removable floating lid. The top lid has a zipped pocket for the odds and ends you need quickly, and it lifts off entirely when you want to save weight, with the integrated FlapJacket flap covering the main compartment in its place.

Compression and attachment. Zig-zag side compression straps cinch the load tight and stable, and the Stow-on-the-Go trekking pole attachment plus an ice axe loop cover the mountain days. There is a dual-access main compartment via the top and a lower zip on the current model.

Durability of the light fabrics

Durability is the standing question with any lightweight pack, and it is where you have to be clear-eyed. The Exos is built from bluesign-approved recycled high-tenacity nylon ripstop, a 100-denier main body with heavier 210 to 400-denier fabric reinforcing the high-wear and tie-down areas. That is a sensible, modern construction that keeps weight down while armouring the panels that take the most abuse.

Testers and owners report the pack standing up well to hard multi-day use, and Osprey specifically redesigned the stretch mesh pockets on recent versions after older models developed a reputation for the front and side mesh snagging and tearing on rock and scrub. The current mesh is markedly tougher. That said, this is still light fabric by design, and it deserves respect on abrasive UK ground: dragging a loaded Exos across gritstone, forcing it through gorse, or dumping it down on sharp rock will wear it faster than a heavy expedition pack shrugs off. Treat it as the precision lightweight tool it is and it lasts for years. The Osprey All Mighty Guarantee sits behind it either way, which is a genuine reassurance the cottage brands rarely match.

Exos 48 vs true cottage ultralight packs

This is the comparison that decides the purchase for a lot of buyers, so it is worth framing plainly. A true ultralight pack from a cottage maker such as Durston, Atom Packs, Zpacks or Hyperlite Mountain Gear will be lighter, often by 200 to 500g, and frequently built from more advanced waterproof fabrics like Dyneema Composite. For a hiker chasing the lowest possible base weight, those packs win on the headline number.

What the Exos offers instead is everything around the weight. Its AirSpeed suspended mesh back is more ventilated than the flat foam panels most ultralight packs use. It is stocked in UK shops so you can fit it before you buy, it comes with a fixed price and easy returns rather than a multi-week international order and a possible import duty bill, and it carries Osprey's warranty. It also carries heavier loads more comfortably than most frameless ultralight packs, thanks to that peripheral frame.

The way to choose is honest self-assessment. If you are a committed weight-counter with a dialled kit list who will use a pack liner and treat the fabric with care, a cottage ultralight pack rewards you. If you want a light, ventilated, framed pack you can buy today, fit properly and trust in British weather, the Exos is the better real-world choice, and it is the one to start with before deciding whether you even need to go lighter. The full field, including the cottage options and where to buy them, is laid out in the best ultralight backpacks UK guide.

The women's Osprey Eja 48

The Exos has a women's-specific counterpart, the Osprey Eja 48, which shares the same AirSpeed suspension, frame, fabrics and feature set. The differences are all about fit. The Eja uses slimmer, S-curved shoulder straps shaped to clear the chest more comfortably, a narrower torso panel, and a hip belt contoured to sit on a woman's hips rather than a man's. It comes in its own size range and carries an almost identical weight and load rating.

If the Exos is the right pack on paper but the harness does not sit right, the Eja is very likely the answer rather than a different model altogether. Both are the same pack in engineering terms, and everything in this review applies equally to the Eja beyond the fit-specific details.

Specs at a glance

Weight

~1.16kg (S) to ~1.18kg (L), with lid

Volume

~48L nominal (approx. 45L to 51L across sizes)

Frame

Peripheral aluminium alloy frame

Back panel

AirSpeed tensioned suspended mesh

Rated load

Up to ~18kg (best in the 11 to 16kg range)

Fabric

bluesign-approved recycled 100D nylon ripstop, 210 to 400D reinforcement

Sizes

S/M and L/XL, ladder torso adjustment ~10cm

Lid

Removable floating lid with FlapJacket flap

Pockets

Front stretch mesh, twin side mesh, two zipped hip belt pockets, lid pocket

Attachments

Stow-on-the-Go poles, ice axe loop, zig-zag compression

Rain cover

Not included (use a pack liner)

Women's version

Osprey Eja 48

Warranty

Osprey All Mighty Guarantee

UK price

~£130 to £215

Pros and cons

• AirSpeed suspended mesh back gives real ventilation, rare at this weight
• Framed and rated for a realistic UK multi-day load (best 11 to 16kg)
• Sub-1.2kg, and drops towards 1kg with the lid removed
• Clean, usable organisation with a big front shove-it pocket
• Ladder torso adjustment fits a wide range of back lengths
• Mainstream UK availability, easy returns and Osprey's All Mighty Guarantee
• Women's Eja 48 offers the same pack in a female-specific fit

• Heaviest option in the lightweight class, 200 to 500g over cottage ultralight packs
• Light nylon fabric and mesh need respect on rock and gorse
• No rain cover included; the body is water-resistant, not waterproof
• Hip belt is comfortable but slimmer than an expedition pack's
• 48L can be tight for winter kit or an untrimmed kit list
• Full RRP around £215 is not cheap, though it often sells nearer £130 to £160

Verdict: is the Osprey Exos 48 worth it?

Yes, and for most UK hikers going lighter it is the pack to buy first. The Osprey Exos 48 does the hardest thing in this category: it makes lightweight backpacking accessible without a compromise that comes back to bite you. The AirSpeed suspended mesh back keeps you cool on the climb, the peripheral aluminium frame carries a real multi-day load onto your hips, and the whole thing still comes in under 1.2kg. You can buy it today, fit it properly, and trust Osprey's guarantee behind it.

The limits are clear and they are the limits of the class, not faults in the pack. It is the heaviest of the lightweight options, so a weight purist will look past it to a cottage build. Its light fabrics need care on abrasive ground, it carries no rain cover, and 48 litres is tight for winter. Load it beyond about 16kg and the slim hip belt starts to show. None of that is a surprise, because Osprey built a lightweight pack, not an ultralight one, and it is honest about what that means.

For the reader moving down from a heavy expedition rucksack towards a lighter, faster way of walking multi-day routes in British conditions, the Exos 48 hits the sweet spot of weight, ventilation, load capacity and buy-it-today convenience better than anything else on the mainstream market. It earns its place as the accessible entry point to lightweight backpacking.

Rating: 4.5 / 5

FAQ

Brand guide: for the full Osprey story, the AirSpeed and AirScape technology behind the packs and where the range fits, read our Osprey brand review.

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