Shade yourself from the sweltering heat of the sun in Sunday Afternoon(R)'s signature hat. With moisture wicking properties to keep sweat from soaking through the hat, it's also UPF 50+ resistant to help protect your face from dangerous UV rays. It features strategic ventilation for comfortable wear, and the Sunday Afternoons(R) Adventure Hat feels nearly weightless as it weighs a mere 3 ounces. FEATURES: 4" downsloping front brim and 3.75" sides with floatable foam core and poly brim wire 7.5" back veil neck flap with lift-up tab UPF 50+ certified breathable sun rating (mesh vents not rated) Strategic mesh ventilation Water repellent / stain resistant Wicking brow sweatband Chinstrap with cord lock External sizing band for custom fit Packs flat for travel Lightweight: 3 ounces Fabric: Body - 100% nylon, Mesh Ventilation - 100% polyester Style: S2A01001 SIZE CHART: Fit the hat slightly above eyebrows and ears to allow front and peripheral vision Measure your head by circling the crown of your head with a string or dental floss(around eyebrows and ears); use a ruler to measure the string Size Medium: 21"-23" Size Large: 23"-25"