The Nike Women's Aeroloft Running Vest is a high-visibility packable activewear vest designed specifically for running. It is made from a blend of polyester and nylon, providing both breathability and insulation. The vest features Nike Aeroloft technology, which uses lightweight down insulation to keep you warm without weighing you down. It also has reflective details for enhanced visibility during low-light conditions. Whether you're training for a marathon or going for a casual jog, this vest is a must-have for any female runner.