The Men's Arc'teryx Atom Jacket - Black Sapphire, is the navy jacket within the Arc'teryx Atom series. A light versatile synthetic insulated jacket that works well as a midlayer and a standalone jacket. Previously known as the Atom LT Jacket, the Atom Jacket is the revised, newly improved generation. It's light, packable and a proven performance warming layer for all occasions whether it be the daily commute to work or alpine ascents. The Coreloft? Compact 60 insulation retains heat when wet and withstands repeated packing and unpacking. The soft, durable Tyono? 20 face fabric resists wind and weather, and stretch fleece side panels improve ventilation and freedom of movement.