UPF 50+ SUN PROTECTION?5.5" Wide brim sun hat with removable neck flap and breathable face flap provides great UV protection to protect your face, ears and neck from harmful UV rays and annoying insects bites during outdoor activities. Women sun flap hat has good performance with strong anti-uv protection and provides 360 degree sun protection. Your ultimate outdoor companion. PERFECT SIZE? Head Circumference is 21.26" - 24.41". Adjustable velcro on the back for a snug and custom fit, one size fits most women. Adjustable long chin strap with cord-lock lets you customize the fit and keeps the hat from being blown away on windy days. The ponytail opening at the back is considerate design for women.