Connectyle mens neck flap sun hat is made of nylon fabric, cool and comfortable. And it is 50+ UPF for complete UV ray protection of your face, ears, and neck. One size fits most adult head sizes between 21.7"-23.3"/55-59 CM. The chin strap holds hat in place on windy days, elastic drawcord with toggle at back for adjustability. The hat features large ventilation meshes on both sides, effectively promoting airflow and heat dissipation. This ensures that our heads remain breathable and dry even during outdoor activities. The hat features 2.95" wide brim that effectively covers our face and neck, providing effective protection against UV rays. The 4.7" short neck flap can not only provide shade for the neck, but also be more ventilated and breathable.