Green Sea Creatures Reversible Uv Bucket Sun Hat By Baby Banz. This Highly Effective Reversible Sun Hat Through A Combination Of Its Wide Brim And Pf (Ultraviolet Protection Factor) Rating Of 50+ Will Block Out More Than 97.5% Of Uva And Uvb Rays. The Hat Features A Large Velcro Closure In The Back Of The Brim To Allow Easy Adjustment For Years Of Wear As The Child Grows. Size: 0-2 Years - Up To 19 (50Cm) Head Circumference (Please Note That 19 Is Quite A Small Head For A 2 Year Old - If In Doubt Go Up A Size As The 2-5 Year Version (49-56Cm) Is Also Adjustable).