This is a UPF 50+ Hat for Premium Sun Protection. What is UPF protection? Follow this link for more information! 
https://www.hatsunlimited.com/what-is-upf/

The Sun 'N' Sand LifeGuard Rush Straw Hat is your classic wide brim sun hat. Featuring a 4" brim, this hat provides perfect amount of coverage during those warm sunny days. This lightweight and comfortable straw hat has a cotton under brim and a convenient chin chord ensuring that your hat will never blow away.

Brime Size 4"