Giro Helmet adjustment system Helios

It's a Roc Loc® 5 Air replacement system fromorigine found on Giro Helios & Eclipse Spherical helmets.

This revolutionary fit system adds a new dimension to helmet performance by improving cooling, fit, comfort and stability. Using a patented design that suspends the helmet slightly above the skull, Roc Lo® 5 Air allows cool airflow to pass directly over your head, further enhancing the performance of the helmet's heat-removing vents and internal ducting. The fit and feel adjustments mimic the Roc Loc 4, allowing you to easily customize the helmet's fit tension and fore-aft tilt in seconds with one hand.