Adjustable Size: Fit for head circumference:54-59cm, suitable for most men, women and teenagers. Widely Application: A wonderful hat for daily wear and out sports, such as beach, street, travel, cycling, driving, golf, tennis, running, fishing and daily walks. Cool Mesh: Made of high quality polyester mesh fabric, lightweight and breathable, make you feel cool and comfortable. Wide Brim Sun Protection: Large brim helps to your face and eyes from the suns harmful rays, a good choice for holiday and outdoor activities. Double Power Source: Featuring a double-power system with solar panel and USB charging, it ensures uninterrupted fan performance under various conditions.