The Arc'teryx Atom LT Vest is a top-selling sleeveless lightweight thermal packable activewear vest for women. It is made from a combination of nylon and polyester, providing excellent insulation and breathability. The vest features Coreloft synthetic insulation, which offers warmth even when wet. It also has a durable water-repellent finish to keep you dry in light rain or snow. The Atom LT Vest has a slim fit and a stand-up collar for added protection against the cold. Whether you're hiking, skiing, or running, this vest is a reliable and versatile choice for staying warm and comfortable.