The most important feature is the Spherical technology, which allows the outer shell to rotate around the inner one in the event of a fall. The fit is comfortable and very secure, thanks to the adjustable Roc Loc® Trail Air fit system, ensuring a snug fit even on rough terrain. The efficient ventilation system makes the Giro Manifest the perfect companion for your next mountain biking adventure. S: Head circumference 51–55cm M: Head circumference 55–59cm Colors: black