If you want the warmth of an Atom Hoody with a wider range of motion and smaller footprint, you 're in the right place. Pull on the Atom Vest when you feel the temperature dropping on longer hikes and climbs or wear it as a midlayer under a shell for touring and wet winter objectives. The Coreloft synthetic insulation stays warm even if you run into light weather, making it a better alternative to down for high-output days year round. Arc'teryx Atom Vest Mens | Black | X-Large | Christy Sports