This hat is made of transparent PVC and a high-quality cotton blend, soft and durable. Size-Adjustable hook & loop strap design on the back, easy to adjust, keep tight and fit most adult head shapes, cap circumference can be adjusted to 21 1/4-23 5/8 inches. The soft brim can protect you from harmful sun damage. The empty roof design is convenient for hairdressing and shading so that your head and hair can breathe. Very suitable for family outings, casual wear, and sports, driving, fishing, picnics, vacations. The perfect gift choice for your friends and family in the hot summer.