Brutal cold weather is where the Arc'teryx Thorium really earns its keep. Packed with 750-fill down and wrapped in a hard-wearing ripstop shell, it's built for long days on the wall when temperatures start to bite. The details are thought through too, including a two-way zip for harness access and oversized internal pockets for warming shoes between attempts. This latest version adds more down, larger baffles and a boxier fit that's better suited to layering. Body: Arato™ 100% Nylon Synthetic Insulation: Coreloft™ 100% Polyester Down Insulation: 750 fill European Grey Goose Down Moisture-resistant Fabric Compressible & Packable Adjustable Drawcord Hem Adjustable Insulated Helmet Compatible Hood Zip Chest Pocket 2 Internal Dump Pockets Fleece Lined Hand Pockets Style Code: X000010657-002291