The Western Mountaineering Flash Vest is a dream come true for lightweight enthusiasts. Weighing in at only three and a half ounces, the Flash Vest is one of the lightest insulated garments you'll ever find. Much like Western Mountaineering sleeping bags, this vest is filled with 850+ fill goose down. While it's comfortable as a layer, when you're wearing the Flash Vest on the outside of your garments, reflective trim helps keep you visible in low light situations. Super lightweight, the Western Mountaineering Flash Vest is sure to become your new favorite layer.