For those in need of serious UV protection, the Sun Runner hat provides excellent coverage without bulk. It has a removable, adjustable skirt that snaps to the main cap and provides wrap-around shelter; the skirt can be removed when you just need the baseball cap. The lightweight Supplex Nylon fabric provides UPF 30+ sun protection, and the TransAction headband wicks moisture away from your head. Mesh side panel vents keep things cool. This hat is ideal for the long full-day mountain pushes when you need all the sun protection you can get.