SunBusters Boys Bucket Hat, UPF 50+ Sun Protection Sun Hat 80% Nylon/20% Spandex Imported Lightweight, quick drying sun protective boy's hat with wide brim. 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. Brim: 2.5" (inches) for Small and 3" for Medium/Large 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.