Material Composition: Polyester is great for protecting your garden, everyday leisure, travel, hiking, walking, outdoor work, long hours of outdoor work, etc.A sun hat that protects from the back of the head to the neck, and provides complete protection against UV rays. It is also great for insects and dust-proof. The back part is adjustable so it can be used by both men and women.Approx. 21.7 - 23.6 inches (55 - 60 cm); Brim part 4.9 inches (12.5 cm); The back is 9.8 inches (25 cm) from sunlight to protect your face and collar.High quality polyester material[Specifications] Weight: 2.8 lbs (0.12 kg); Diameter: 15.7 inches (40 cm); Brim: 4.9 inches (12.5 cm); Head circumference: 21.7 - 23.6 inches (55 - 60 cm).