Giro Ionos Road Cycling HelmetIonos is the most ventilated and technologically advanced road cycling helmet Giro has ever created. Our proprietary in-mold composite sub-frame (I.C.S.ô) provides the strength to support 21 of the largest vents ever carved into a helmet. These massive ventsócoupled with an intricate network of internal channelsócreate a cooling system we call Wind Tunnelô ventilation. The difference is remarkable and after one ride youíll agree: the Ionos is the coolest, best-ventilated helmet available. This is the reason that Grand Tour champions like Lance Armstrong and Alberto Contador choose Ionos to stay cool on the hottest days.