Osprey Mutant 28 Pack | Performance

This is the second iteration of the smaller of Osprey’s two Mutant technical mountain packs – there’s also a larger 38-litre version – and it’s a classic slice of Ospreyness with tons of refinement and a bunch of carefully thought-out features that mark it out.

Access is via a zip-open panel up top that makes getting stuff in and out straightforward, but you also get a handy and quite substantial top zipped external pocket plus a mesh one on the inside of the zip-open flap complete with a key-clip. Yes, climbers have keys too.

Then there’s the back system. Classic alpine packs use thermomolded or fabric backs to avoid snow sticking to them, which is all well and good, but can make for a sweaty contact area. Osprey instead use a special reversed spacer mesh over a ridged foam pad, which shrugs off snow, but feels considerably less sweaty when the going gets hot.

Inside there’s a removable HDPE framesheet with T6061 aluminium central stay that manages to support reasonably heavy climbing loads – rope, rack, spare clothing, bivi kit and all – without undue discomfort. You can take it out too if you want, but we didn’t bother. The pack only weighs 1000g anyway.

Everywhere you look are neat little Osprey touches that really do make a difference. The shoulder straps are similarly foamed, meshed and vented and have just the right degree of support. The effective zig-zag compression strap can be locked off so you can compress different areas of the pack independently.

And then there’s the hemet carrier. It’s a stretch mesh, like a sort of glorified hair-net, that emerges from the same pocket as the rope strap and simple holds a helmet securely in place on top of your pack. Genius. If you’ve ever struggled to carry a climbing helmet on a fully-loaded pack, you’ll know exactly what we mean.

What else? The ice axe attachments aren’t strictly speaking an Osprey original touch, but work brilliantly with leashed or modern leashless tools and have snow-resistant shock-corded top loops, our default choice.

Mini gear-loops on the hip-fins work well, but manage not to obstruct your harness and can be reverse clipped if you prefer to have them out of the way. And finally, the build quality feels sturdy and solid, but in a refined sort of way.

Our one slight quibble is over how that mesh-covered back system will perform with heavy use, but the rest of the pack feels reassuringly light but solid.