Shoei Kagayama 4 X-Twelve Street Bike Racing Motorcycle Helmet - TC-5/Medium Aerodynamic Properties Are Maximized Through Extensive Wind Tunnel Testing and Professional Riders Feedback Dual Layer EPS Liner Enhances Impact Absorption and Ventilation Five Shell and Six EPS Liner Sizes Present Increased Fit Options That Help to Comfortably Fit Most Head Sizes Air Scoop 3 Intake Vent Is Positioned to Maximize Air Volume Into the Helmet Interior DOT approved. Meets the FMVSS 218 Standard.