Thorium AR Hoody The Thorium AR Hoody combines ergonomic fit, premium craftsmanship and carefully selected fabrics. Lofty 750 fill European grey goose down delivers exceptional warmth for little weight, is durably resilient, and packs easily. The outer is soft, durable Arato™ 40 nylon. This lightweight material withstands abrasion, packs compactly and has a DWR finish to repel moisture.CAREFUL DESIGNArc’teryx designs are careful and intentional, and the Thorium’s elevated performance comes from focused construction and patterning. The women’s specific Athletic fit is streamlined and layers easily under a hardshell in cold conditions. Articulation built into the sleeves and gussets under the arm provide a level of freedom of movement not often found in an insulated jacket. Because the Thorium AR is intended as a midlayer, Arc’teryx is able to use sewn through construction to further reduce weight and increase packability.MAPPED for PERFORMANCEArc’teryx Down Composite Mapping technology combines the goose down insulation with panels of Coreloft™ synthetic insulation in areas prone to moisture. Used in the hood, cuffs and under the arms, the Coreloft™ insulates even if wet. Down is used in the sleeves and around the body’s core. The insulated StormHood™ fits close to the head for efficient thermal performance and a high level of visibility, and two zippered pockets secure small essentials.