For sun protection and cooling ventilation on the water or trail, the Sombriolet Sun Hat from Outdoor Research boasts UPF 50, crown venting, and lightweight breathable fabric. Flexible piping along the brim resists wind. Cotton and nylon fabric blend at crown and brim. Lightweight, breathable, moisture wicking fabric. Wicking TransAction headband. UPF 50 for maximum protection from harmful UV rays. Crown venting to help keep you cool. Flexible brim piping resists wind and helps keep hat in place. Foam stiffened brim floats. Mesh lined crown. External drawcord adjustment. Removable chin cord. Dark under brim helps reduce glare.