Small-Medium: Head circumference 21.5-22.75" (Crown depth: 3.75") Large-X-Large: Head circumference 23-23.5" (Crown depth: 4") | Sizing Tip: If you are between sizes, we recommend sizing down for the most comfortable fit. EXCELLENT SUN PROTECTION: Featuring a 4" wide brim, the Solbari Holiday Sun Hat provides excellent shade for your face, neck, and eyes. Designed with UPF 50+ sun protection, and for individuals with sensitive skin, it effectively blocks harmful UVA and UVB rays. BROAD COVERAGE & REVERSIBLE DESIGN: With a generous 4” brim, a shapeable internal wire for versatile styling, and an adjustable and removable drawcord to keep it secure in windy weather, this women’s sun hat is ideal for any adventure or outing. It also benefits from being fully reversible. NATURAL FIBERS: Designed for women with sensitive skin, it is made from a 50% cotton / 50% linen blend. This sun hat offers breathability and versatility, pairing perfectly with any outfit to keep you cool and comfortable in the heat. Our Holiday Sun Hat is sure to be your go-to sun hat for maximum coverage and style, with a flexible brim length of 4" that benefits from an internal wire, giving it a fully customizable shape. Adjustable to your size and style, the hat features a reversible double layer of luxurious cotton-linen blend fabric with a drawcord to keep it secure.