The men’s NANO PUFF Bivy pullover is lightweight, warm, windproof, water-resistant, and highly compressible: everything you need on the ascent. A recycled poly ripstop shell has a DWR finish. Inside, PrimaLoft Gold insulation Eco is the top synthetic warmer around, maintaining 98% of its warmth even when wet. Brick and horizontal quilt lines stabilise insulation with abrasion-resistant stitching. The hood fits under the helmet, with elastic binding to increase comfort. The front zip has a wicking inner storm flap and a zipper garage. There is a large kangaroo handwarmer pocket. The zip drop in front torso pocket doubles as a stuff sack, holding the whole jacket. A deep venting front zip, elastic-bound cuffs and a drawcord-adjustable hem help with fit and protection.