THE GIRO AEON™ - THE LEADING COMBINATION OF LIGHT WEIGHT, COMFORT AND COOLING PERFORMANCE. Imagine a helmet that gives you an advantage every time the road climbs or the heat turns up. Until now, you couldn’t get the benefits of lighter weight and better ventilation in a single helmet. But the new Aeon weighs only 222g in a CPSC approved size Medium. Yet it also provides cooling power equivalent to the most ventilated helmet ever made, the Ionos™. Plus it offers the luxurious feel of Roc Loc® 5, and an innovative thermoformed Roll Cage reinforcement. If you’re looking for the best balance of weight, ventilation and comfort, this is the new standard.