展开The Arc'teryx Atom LT Hoodie is crazy light, breathable, and warm. It's not hard to see why the Atom remains one of the best-selling and highest-rated midlayers year after year, beloved by skiers, hikers, climbers, and townsfolk alike. It's great on its own for warmth when the weather's not too bad, and the air permeable Tyono shell with Coreloft insulation really shine when used to add warmth under a shell without any sacrifice to airflow or breathability.