AGV K5 Adult Enlace Street Motorcycle Helmet - Matte White/Black / X-Large External shell is constructed of CAF (Carbon-Fiberglass) and is manufactured in 2 sizes EPS inner lining available in 4 sizes with 4 different densities Shell and EPS dimensions are optimized using the FEM (Finite Elements Analysis) Ventilation system: IVS consisting of one chin guard vent, 2 front air vents and an air extractor with rear on/off switch, developed in the wind tunnel for optimum air flow and stability Breathable Lycra micro-porous liner and Dry-comfort fabric with sanitizing treatment using CoolMax fabricsCentral front air vent built into the shell profile with direct high air flow channel