For the mountain expedition and ultimate treks. The Rab Men's Neutrino Down Jacket has the perfect combinations of technologies. The best of these is the Pertex Endurance is designed to provide significant weather protection for insulated garments and sleeping bags in extreme conditions. It incorporates an ultra-thin air permeable coating that is both highly breathable, water and wind resistant. This layer protects the insulation from the elements maintain loft and retain warmth.