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Sizes: M(19.5-20.5"), L(20.5-21.5").SUN PROTECTIONDon't let the sun spoil your child's fun. Experts warn that up to 50% of skin damage from the sun occurs before a child reaches the age of 18. Sun protection is a must for children of all ages who enjoy spending time outside, whether hiking, biking, camping or by the water.Lightweight sun hat made from water-resistant Supplex nylon fabric.Sun protection with a UPF of 50.Flexible down sloped brim offers great coverage for face, ears and neck.Top of crown has mesh for air circulation and moisture release.Decorative ribbon trim on crown.Chin strap with cord lock for size Large.Chin strap with breakaway buckle for size Medium.Hat crushes for easy packing.Avg. Wt. 1.3 oz.