Giro Aeon Road Bike Helmet (Blue/Black, Large) Set and forget Roc Loc TT Fit system creates a self-adjusting fit with secure feel and helps improve aerodynamics by allowing back of the helmet to be closed off to the wind In-mold polycarbonate shell with EPS liner Internal channeling ventilation with 24 wind tunnel vents and X-Static padding Featherweight webbing with Slimline buckle Thermoformed SL Roll Cage reinforcement