Built to handle a range of environments – cold ones – the Thorium delivers serious warmth. Packed with 750 fill-power Responsible Down Standard certified grey goose down, it offers outstanding thermal performance for its weight. Down Composite Mapping™ strategically places Coreloft™ synthetic insulation in areas prone to moisture, the light, durable Arato™ 30 nylon shell has a DWR treatment for water repellency, a bio-derived liner reduces petroleum use, and the insulated adjustable StormHood™ adds even more warmth.