Buyer beware - this hat does not block UV light.  I bought the 3XL and I am happy that it fits, but the whole reason for buying this hat was for sun protection, and my face and ears are still getting sunburned while wearing it.  The hat is 100% cotton and cotton only blocks about 5% of the total UV light from the sun, and I have the burnt skin to prove it.  I am going to purchase the Sun Guard laundry treatment and see if that helps.