Traveelor Star Motorcycle Helmet Half Helmet Winter Helmet(multi Styles to Choose)-large Size Size: Large (Adult) (56-60cm) (22.04''-23.62'') (Hat Size: 7 3/8 - 7 1/2) Injection Molded Polycarbonate and Thermoplastic Composite Shell. High impact resistant thermoplastic outer shell Helmet Liner is Lightweight, Soft and comfortable interior.Fully removable/washable liner. Ventilation: 5 vents front and rear, patent breathable mesh lining Sleek and Lightweight Open Face Design.Low profile design.Double D-ring retention system Meets or Exceeds FMVSS-218 and DOT Safety Standards,In 2016, the latest version