SIGGI Womens Floppy Summer Sun Straw Hat UPF50 Foldable Panama Soft Breathable Fabric:100%cellulosic fibre. FOLDABLE: soft straw fabric, foldable and packable for travel. DETACHABLE CHIN STRAP: adjustable for a better fit; won't blown off when it gets windy. FREE SIZE: an adjustable tape built inside the sweatband. Best fit for 56-58cm 22"-22.8" 7- 7 1/4. VENTILATED: perfect for beach vacation, also great for summer rides, fishing and hiking. WIDE BRIM: measures 3.7" in length, not only looks stylish, but also wide enough to shade uv rays effectively.