Balconi hats are perfect for a run on a cool day, hiking, or just hanging out. Designed to keep your ears and head warm, while allowing breathability from the top. The Hydro-Breeze wicks away sweat and heat from the head while keeping you cool. Stretch fit, one size fits all. Flexible bill. Washable. Eco-friendly. Material: Acrylic (Endurance), Polyester/Lycra blend (Hydro-Breeze). Patented and proudly made in the USA.