SUN UV PROTECTION: Large enough to block most of the sun's UV rays and provides excellent full coverage of the head and face and the entire neck, protecting your skin and eyes from strong sunlight. It is a great accessory for outdoor use in summer. BREATHABLE & COMFORTABLE: This Panama hat is made of high-quality paper straw. There is a cotton sweatband inside the hat, breathable, sweat-absorbing, moisture-wicking, comfortable to wear. The wonderful woven craftsmanship makes them very durable. ADJUSTABLE CHIN STRAP: One size fits most men and women. Adjustable, you can adjust to a suitable size depending on comfort level. This sun hat with adjustable chin strap for a secure fit, won't blow away in the wind. Hat circumference: 22-22.8 inches (56-58 cm); Hat brim: 3.5 inches (9 cm); Hat diameter: 12.6 inches (32 cm) FOLDABLE & PACKABLE: Packable design makes it easy to carry, you can easily fold it up and put it in your backpack or suitcase. It saves a lot of space and is convenient. Perfect for beach vacations, cruises, summer tours, travel, fishing, hiking or summer outings.