Arc'teryx designed its Men's Nuclei AR Insulated Jacket to perform in some of the most rugged and remote mountain environments on the planet. A Windstopper shell, taped seams, and a helmet compatible Stormhood make the Nuclei AR both a capable outer layer and efficient midlayer. Its Coreloft insulation is composed of crimped and siliconized polyester fibers, making the jacket light, breathable, water resistant, and quick to dry. Its gusseted underarms grant full mobility while climbing, and its athletic fit is tailored to accommodate alpine pursuits with an anatomical shape that enhances range of motion while eliminating unnecessary bulk. An included stuff sack allows the jacket to be clipped to a harness or stuffed in a ski touring pack, and the internal mesh pocket is ideal for warming frozen skin glue or a pair of glove liners.