The Ionos Ionos is the most ventilated and technologically advanced road cycling helmet Giro has ever created. Our proprietary in-mold composite sub-frame (I.C.S.™) provides the strength to support 21 of the largest vents ever carved into a helmet. These massive vents, coupled with an intricate network of internal channels, create a cooling system we call Wind Tunnel™ ventilation, making Ionos the coolest, best-ventilated helmet available. Perfect for keeping Grand Tour champions like Lance Armstrong and Alberto Contador cool on the hottest days and over the most tortuous Alpine climbs.