US Style Boonie Hat - Olive Green
The US "Boonie" Hat was made for the Jungle originally but has claimed popular appeal for any environment. It is perfect to keep the sun off and give shade to your eyes but works equally well as a protective layer in the winter.
It is available in a range of sizes and, to give you a guide a large is a 59. A 58/59 is probably the most common hat size for men in the UK.