Fabric: 100% Nylon, lightweight, fast-drying and breathable fabric. UPF 50+ rated material will protect your face and eyes from harmful UVA and UVB rays Adjustable & Unstructured: Hook and loop fastener at back for easy adjustment, and unstructured construction provides a comfortable fit. One size fits most head sizes about 22.0"-23.2" Reflective Outdoor Cap: The silver accents on the back closure for increased visibility & safety in low light or after dark. The pre-curved 3.0" long visor keeps the sun form your face and eyes Breathable & Ultra Light: The mesh side vents for superior airflow, keep your head cool and comfortable. This is the perfect hat for fitness, running, cycling, tennis, golf, fishing, hiking, and traveling Water-Resistant: Made with water-repellent nylon fabric, it is easy to shed water quickly, keeping your head dry and comfortable. Great for most outdoor activities and sports