The pattern for the Bionnassay 500 was specifically researched to ensure maximum freedom of movement during mountaineering whilst providing protection from the elements. The challenge here was to create a jacket that stands out in terms of design and provides a solution to a common problem: how to find the right volume that enables mountaineers to raise their arms without the jacket riding up around the waist and restricting long-range vision. As a result, the Bionnassay 500 is manufactured with its arms upright, so that when raising their arms the user actually straightens out the material, reducing the ruffling which normally occurs.