Shoei Assail X-14 Sports Bike Racing Motorcycle Helmet - TC-1/X-Large Aerodynamic properties are maximized through extensive wind tunnel testing and professional riders' feedback DOT approved. Meets the FMVSS 218 Standard. Four shell and five EPS liner sizes present increased fit options that help to comfortably fit most head sizes Impact absorStandard Rear Flaps can be replaced with optional, narrower flaps to customize aerodynamics, dependingbing EPS liner throughout the entire chin bar with Cheek Pad Cooling System