100% Polyester.Button closure.One size fits most: Casual style sun hat, snug and cosy fit. Hat Circumference: 21-23, Hat Height: 4.33 inch, Brim Length: 3.35 inch, Chin Drawstring Length:12.99 inch. One size is suitable for most women..Functional and versatile:The brim is large enough to shade forehead. Inside of the hat is a breathable mesh layer, which can greatly improve cooling, comfortable and airflow. Especially, a ponytail opening in back is considerate design for women. The buttons on both sides of the hat can give you more different styles..Material: This fashion fishing sun cap is made of quick-drying, breathable polyester.It provides you better protection from sunshine and damaging rays for face and neck..Adjustable drawstringa: Adjustable chin drawstring for fixing the sun hat, especially in windy days. And another drawstring behind the fishing hat is for adjusting the hat circumference to make it most suitable..Easy storage:Rolled up convenient to carry and absolutely save lots of space. It is a perfect hat for beach, fishing, pool, park, hiking, camping, travel, hunting, gardening or any outdoor sports and activities.