Built to handle a variety of environments – especially cold ones – the Thorium delivers substantial warmth. Filled with 750 fill-power Responsible Down Standard (RDS) certified grey goose down, it offers exceptional warmth-to-weight ratio. Down Composite Mapping™ strategically places Coreloft™ synthetic insulation in areas that are more susceptible to moisture, while the lightweight and durable Arato™ 30 nylon shell has a DWR treatment for water-repellent properties. A bio-based lining reduces petroleum use, and the insulated and adjustable StormHood™ hood provides extra warmth.