SIGGI Womens Bucket Boonie Fishing Cap Summer Beach Sun Shade Hat SPF 50 cotton/polyester FREE SIZE: with a size adjustable string or bow at back. Make it best fit for 55-58cm 21.6"-22.8" 6 7/8 - 7 1/4. FOLDABLE: folds up easily, compact and perfect as a outdoor or vacation hats. DETACHABLE CHIN STRAP: adjustable for a better fit; won't blown off when it gets windy. UPF 50+: this sun hat has passed UPF 50+ test, it could block 97.5% or more of sun UV rays. When shipped by Comhats,it will be fulfilled within 2 days. Usually it takes 8-10days to be delivered. If you hope to get a PRIME service, please notice to choose "Fulfilled-by-Amazon".