The XD-4 offers three distinct confi gurations depending on rider preference or riding conditions. Change the look every time you ride — or even during the same ride. Arai's patented FCS Cheek Pad design delivers comfort and support, and it features our exclusive 5mm peel-away custom-fit layer. The larger, sculpted vents improve ventilation efficiency as well as helmet stability on your head at speed. These top-diffuser-vent ports nearly double the XD4's airflow, while its shell shape provides better aerodynamic stability at higher street speeds in concert with its high-flow peak and side cowl vents. DOT FMVSS No. 218 Certified Offering three distinct configurations, allowing the user to choose which works best for their riding needs, the new XD4 is similar in appearance to the previous XD3 but greatly improved in all-around performance. The combination of the new comfort headliner, with micro-fitting 5mm peel-away temple pads, and our patent-pending FCS cheek pad design, also with 5mm peel away layers, add a new dimension to the concept of helmet fit and customization. It takes a unique sense of commitment to continually strive to improve your product – especially when it's already regarded as the very best.