Suede leather with cool flow through mesh, adjustable chin strap and leather hat band. Fully foldable, waterproof and super light weight. Sizes are: / S - 6 7/8 - 55 cm or 21.65 in / M - 7 1/8 - 57 cm or 22.44 in / L - 7 3/8 - 59 or 23.23 in / XL - 7 5/