SunBusters Boys Flap Hat, UPF 50+ Sun Protection Sun Hat Solid: 100% Taslan. Print: 80% Nylon/20% Spandex Imported Lightweight, quick drying sun protective legionnaire style hat with sturdy yet flexible bill. Perfect for infants, toddlers and big kids. EXCELLENT SUN PROTECTION: Swimwear fabrics are rated UPF 50+ and provide maximum UV sun protection by blocking 98% of UVA + UVB sun rays, wet or dry; similar rating as SPF for sunscreens. Covered areas don't need sunscreen. Optimal protection for face, neck and ears Made of the same great fabrics as our swimsuits so they can be worn in and out of the water SIZING: For optimal fit, wrap a soft measuring tape around head about 1" (inch) above eyebrows. If in between sizes, go up a size.