This is a hat from Toshi, a popular brand in Australia known for its strong UV protection. The Toshi bucket hat features UPF 50+ sun protection. UPF stands for "Ultraviolet Protection Factor" and indicates the level of UV protection offered by clothing, etc. A higher number signifies greater UV protection. Size: S Inner diameter approximately 15 cm. Price: Purchased for 44.99 Australian dollars, but unfortunately, it doesn't fit my daughter, so I am selling it. There is a small stain on the inside. Please understand.