This hat provides maximum sun protection. It is oblong in shape which gives additional protection to the face and back of your neck. The fabric is tested to exceed UPF 50. The brim is 3.25" wide on the sides and 4.5" on the front and back. Both sides of the hat have a mesh screen providing air flow around your head. Sewn inside of the brim is foam which allows the hat to float in water. There is a small hidden pocket in the crown which will hold a credit card, driver's license and a few dollar bills. The size of the hat can be adjusted with a draw cord in the back and it also comes with adjustable drawstrings. If you are looking for maximum protection, this is your hat. The fabric is a light weight, durable, fade resistant nylon.