HJC CL-17 Mech Hunter Full-Face Motorcycle Helmet (MC-4F, X-Large) Advanced Polycarbonate Composite Shell - Lightweight, superior fit and comfort using advanced CAD technology Anti-Scratch Pinlock ready Face shield (HJ-09) New 3D design provides 95 percent U.V. protection; Side shield lock mechanism for a ultra-secure seal RapidFire Shield Replacement System; Simple and secure shield ratchet system provides ultra-quick, tool-less removal and installation for efficient operation 2-Stage shield closure system with one-touch center open/close shield locking system makes for an extremely tight and secure seal ACS Advanced Channeling Ventilation System; Full front to back airflow flushes heat and humidity up and out