Outer shell made of polycarbonate, the same as high end motorcycle helmets, equipped with the original Alcantara. Inner shell is made of polystyrene with variable density providing a better dissipation of energy on impact. The internal comfort foam, ensures a constant thickness over years of use and the semi-rigid jugular eliminates helmet tipping in the event of violent movement. The internal comfort foam is removable and held in place by a clip system that is more secure than a Velcro system. The liner is machine washable to rid of odor. Shells come in small, medium, large. Each shell fits three to five different hat sizes. This accommodates for young riders growth as well as hair cuts/growth, simply buy a new liner, not a new helmet. Equipped with a superior ventilation system. Air is channeled from the front entrance, over the rider's head, and out the back vents, around comfort foam which prevents sweating.