Arc'teryx Atom Vest - Women'sWhether used as a midlayer or on its own, the Arc'teryx Atom Vest is highly versatile for all seasons, terrains, and physical activities. Thanks to its top notch insulation, materials, and design, this newest iteration continues to deliver legendary performance. The innovative Coreloft Compact insulation offers warmth even when damp and can withstand repeated packing and unpacking, while the wind and water resistant Tyono 20 shell ensures durability.