Lanzom Womens Big Bowknot Straw Hat Floppy Foldable Roll up Beach Cap Sun Hat UPF 50+ (Beige)

Would someone please post actual circumference of the part of the hat that sits on the head? I hesitate to buy it, as I have a huge head. Thanks!

The description says this hat is straw and made of cotton. how was the upf rating of 50+ achieved?

How do you fold the hat without causing damage?

What shade of red is the watermelon red? Does it actually look red?