100% Polyester FEATURES: Moisture wicking, comfortable and quick dry polyester mesh construction. MATERIAL: Polyester and cotton, thin soft and lightweight material, soft hand feel. SIZE: Adjustable size fits most, head circumference 21.6-24.4 inch (55-62cm). IDEAR FOR: Running, golfs, tennis, Baseball, and any outdoor activities for shade. CUSTOMER SERVICE: Any dissatisfaction can be quick returned.