The Neutrino Jacket is remarkable for its combination of durable 20D nylon shell material (Camp's proprietary Araneum) and Primaloft® synthetic fill, while maintaining that critical property of superb packability that Essential garments from C.A.M.P. are known for. Araneum is a spectacular insulating shell material because it is windproof without the use of any coatings. This means the fabric has a natural tendency for trapping heat, yet it remains one of the most packable materials on the market. Compare the Neutrino conceptually to the traditional 'softshell' design, but add insulation that works even when it's wet and better protection from the wind. The full-size hood, full-length 2-way main zipper, inner and outer pockets and a special Stow-Away Pocket (self-contained packing pockets standard on Camp Essential outerwear) round out the features on this advanced shell/layering piece. Araneum 20D lining. Full-size hood. Zippered hand warmer pockets. Inner chest pocket. Lycra cuffs.