PATAGONIA Reversible Bivy Down Vest Classic Tan. A water-resistant, reversible, insulated down vest with fleece lining that provides the perfect combination of warmth, functionality and durability. Water-Resistant Shell with Recycled Down Insulation. Shell: 100% recycled polyester with DWR; yoke: recycled nylon; reverse side: polyester (70% recycled) ¼"-pile fleece; insulation: 600-fill-power Recycled Down. Classic vest design features a front snap-placket and a warm, comfortable down-filled collar to protect your neck. Reverse side has a patch-on, left-chest zippered pocket made with recycled nylon and side-entry handwarmer pockets with elastic binding.