The NRS Havoc Helmet is your one-size-fits-most solution to whitewater safety. Protect nearly any adult with the same helmet. No more mixing and matching. Plush FIT pads in key contact points provide extra comfort. The DialFit system lets you quickly and easily adjust the fit to accommodate almost any head size. Shell material: ABS plastic. Liner Material: closed-cell EVA foam. Vented: yes. Adjustment: DialFit adjustment. Ear coverage: no.