Polypropylene HD external shell is lightweight with excellent impact absorption. Ventilation channels with 14 air intakes shaped for preventing debris entry and internal channels for enhanced breathability and wearer comfort. Moisture-wicking fabric technology for all-day comfort. Chinstrap loop enables the wearer to securely attached the helmet to a harness. Helmet size adjusting system that allows for an easy and secure fit by turning the large diameter dial. The system moves up and down to adapt to a range of head shapes. ANSI Z89.1 TYPE I - CLASS C HT LT EN 12492.