As you’d expect from a climbing brand, this is made from tough, durable materials. The textured fabric feels like it could be scraped over rocks without harm and the watertight zips are protected by thick vinyl fl aps. It should cope well with rough usage. The penalty is that it’s heavy – the equal heaviest of all the packs tested. The harness is substantial and the thick hipbelt very supportive – so it will handle heavier loads than most of those tested. The shoulder straps are linked across the bottom of the pack so when you lift one shoulder that strap lengthens while the other one shortens, an idea first introduced in Aarnpacks. Combined with the pivoting hipbelt this makes for a stable pack that moves with you when scrambling or climbing. The Mercury has big, roomy pockets and panel access to the main compartment. It would be good for tough trips on diffi cult terrain with heavy loads. I don’t think the weight and robustness is needed for most backpacking, though.