Nauticalia

These hats are foldable to about quarter of their normal size, and supplied with a storage/transportation bag to keep them in shape once you've done so.

They are made in Australia, and excellent quality. Made from soft, lightweight and waterproof cattle hide suede. Excellent sun protection - rated UPF50+.
 
For sizing chart, please enlarge sizing image - measure head just above eyebrows and ears.