Durable cotton canvas, with cool flow through mesh, adjustable chin strap and leather hat band. Fully foldable and waterproof. Sizes are: / S -7 - 56.5 cm or 22.24 in / M - 7 1/4 - 58 cm or 22.83 in / L - 7 3/8 - 59.5 or 23.43 in / XL - 7 5/8 - 61 cm or