The Arc'teryx Atom Women's Vest is a star of a midlayer whether you’re laying over it, or tossing it on to keep your core comfortable. A trimmer pattern cut this stays close to the body through the chest, waist, hip, and thigh for a profile to eliminate bulk. Side stretch panels make this move with you for a vest that fits comfortably over first layers and tees, unnoticeably under shells, both light and winter weight. The Coreloft™ Compact insulation retains warmth even if it gets wet and, even better, is designed to withstand years of packing and unpacking. This vest is built to compress, and packs into its own pocket, and a corner of your pack, as that warming layer when you take a break.. or the weather takes a turn. With a durable Tyono™ 20 shell that resists wind and light weather this is a vest for active days in winter and sudden surprises in summer.