A warm down vest - it's a winter necessity. Born from an alpine-proven design, refined to perform as a versatile standalone, the Thorium is the one you reach for before stepping out into the cold. The 750 fill-power Responsible Down Standard certified grey goose down delivers excellent warmth for its weight. Down Composite Mapping strategically places Coreloft synthetic insulation in areas prone to moisture, the bio-derived liner reduces petroleum use, and the light, durable Arato 30 nylon shell has a DWR treatment for water repellency.