C91 Modular Helmet. The C91 helmet will offer riders some of the best features on the market at a budget-friendly price. Starting with the Advance Polycarbonate Composite Shell. It provides a lightweight helmet with a superior fit and comfort using advanced CAD technology. The chin bar operates with an easy to use a single lever and is user friendly with gloves. It also includes an internal sun shield with a manual mechanism that moves forward and back with ease. The large top vent allows airflow ventilation throughout the deep EPS channels of the helmet, keeping you cool on rides. The SuperCool top liner and cheek pad interior gives additional cooling features with its moisture-wicking anti-odor fabric. The C91 is also Smart HJC ready to accept the 10B or 20B Bluetooth systems (sold separately). Advanced Polycarbonate Composite Shell with Adjustable Chinbar: Lightweight, superior fit and comfort using advanced CAD technology.