Rho Series: Thermally efficient moisture wicking base layer. LT: Light Weight. Built with highly durable top performance materials but designed with a streamlined minimalist set of features to provide very light weight. The Rho LTW Beanie from Arc'teryx is a lightweight wool/spandex blend perfect for layering under a helmet or hood. Breathable wool/spandex fabric and a double layered headband wicks moisture so you stay dry all day long. The Rho LTW Beanie features the signature Arc'teryx Bird logo embroidered on the side. Features: Embroidered logo Six dart construction Double layered headband Weight: 30 g / 1.1 oz Activity: All Around Materials: MAPP Merino Wool