HJC RPHA 1N Helmet. The RPHA 1N was designed and developed after several years of focused efforts and crucial feedback from top world-class athletes in MotoGP. HJC's top engineers went to work and created a race-bred helmet that is truly worthy of top race circuits around the world. The RPHA 1N is the very same model used by HJC's world-class athletes in both MotoGP and WorldSBK. Features P.I.M. Plus (Premium Integrated Matrix Plus) Reinforcement Materials, Including Carbon and Carbon-Glass Hybrid Fabric Aerodynamic Shell Design. 5 intake, 4 exhaust vents "ACS" Advanced Channeling Ventilation System Pinlock®-Ready, Anti-scratch, HJ-35 Shield Easy Attachment System Allows Tool-Less Shield Replacement SilverCool™ Enhanced Moisture Wicking and Quick Dry Removable, Washable Crown and Cheek Pads Includes: Breach Deflector, Chin Curtain, Tear-Offfs, Clear Extended Aero-Spoiler Speaker Pockets for Bluetooth Communication Standards: FIM, ECE, & DOT Approved Sizing Wrap a tape measure horizontally around your forehead. Select the helmet that is the closest fit to that size. A helmet should fit snug on your head. If it moves while wearing, it is too large. If it is painful to wear, it is too small. Size Chart Size Head (CM) 2XS 52 - 53 XS 53 - 54 S 55 - 56 M 57 - 58 L 59 - 60 XL 61 - 62 2XL 63 - 64
