The Outdoor Research Unisex Swift Air Cap is perfect for more than just training. It offers UPF 40+ sun protection on the crown of your head and mesh panels for superior ventilation in warm weather, packing in function and performance. This cap is breathable, lightweight, and water-resistant, providing protection in multiple forms. A quick-release back buckle ensures a secure and comfortable fit for all-day wear. The TransAction™ internal headband absorbs and wicks moisture to keep your face and head dry. The flexible brim makes it highly packable, allowing you to stash it away in a hip pack or running vest when not in immediate use. Weighing only 48g, it's ideal for weight-conscious thru-hikers and trail runners. The fabric is bluesign® approved 60% Recycled Nylon, 40% Nylon Shell with 100% Polyester Mesh.