100 SPF/ UPF 50+ Adjustable Lightweight, only 2.5 oz 4 ¾" Brim for Maximum Sun Protection Adjustable: One size fits most Made of 100% Polyester Approved by Melanoma International Foundation & American Melanoma Foundation The Sun Protection Zone Outdoor Booney hat features a new lightweight breathable fabric that provides maximum UVA and UVB protection. The brim is 4 inches in the front and back to shade the face and neck. A pull string adjusts the sizing to fit most adults and the adjustable chin strap keeps the hat in place in windy conditions. It floats (just in case) and should be hand washed to preserve the shape. This ultra-protective micro-fiber and mesh hat is approved by the Melanoma International Foundation and is perfect for boating, hiking or any outdoor activity. At only 2.5 ounces, this lightweight hat is adjustable and has an SPF rating of 100 and UPF 50+.