Montane makes a wide range of jackets, some with a focus on extreme light weight, others on performance. At 350g the Air sits somewhere in the middle and offers a trim versatility for mountain and outdoor use throughout the year.
The cut is surprisingly roomy, and is particularly generous around the arms - allowing for good movement when scrambling or climbing. Length-wise it just covers the buttocks and comes with good hem (drawcord) and excellent wrist (hook and loop) adjustment. The stiff-peaked hood offers solid protection from the elements and is cinched down via two drawcords at the neck and one at the rear. The tidies for the former are on the inside of the jacket, which stops them from flying around in extreme winds, but can prove a little irksome during initial adjustment.
The pockets are very well chosen on the Air. They come via a pair of hand pockets which, although potentially obscured by rucksack hip belts, cleverly extend all the way up to the top of the chest - making them far larger than you might expect and easily capable of holding a map or equally tall item. Two chest pockets, meanwhile, savvily sit on top of that inner pocket flush against the outer material. They're small, but are handy for quick-access items. All the zips bear a water resistant AquaGuard design, with the main one carrying a lower popper to secure the inner stormflap and hold it in place.
Technically, the Air is a very impressive shell: its Pertex Shield AP fabric returns a massive 20,000mm of hydrostatic head in lab conditions (at least double what many may consider effectively waterproof for outdoor use). When in use in rough British conditions we found it to perform just as well as expected. The cut, design and seams are just as important as the fabric for real-world use, and Montane have done an excellent job here.
In conclusion: there are very few British conditions that the Air wouldn't tackle confidently, and it's light and breathable enough to be carried during the summer months too. A superbly versatile purchase.