Baby Banz Baby Boys' Banz UPF 50+ Reversible Hat 100% Polyester Imported Hand Wash Material: 100 percent polyester pf(ultraviolet protection factor) rating of 50+ and will block out more than 97.5 percent of UVA and UVB rays Most UV hats are made of synthetic material which does not breathe making it very hot for the wearer Poly blend allows for breathability, quick drying and comfort Features Velcro closure in the back of the brim to allow easy adjustment for years of wear as the child grows Baby banz fit 0-2 years old ( up to 19 inch head circumference )