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. The Aeon combines the benefits of lighter weight and better ventilation in a single helmet. The Aeon weighs only 190g in size Medium. Yet it also provides great cooling power. Plus it offers the luxurious feel of Roc Loc® 5, and an innovative thermoformed Roll Cage reinforcement. If you're looking for the optimal balance of weight, ventilation and comfort, this is the standard.