ABS hard shell technology Increases visibility with large reflectors Can be used with hair tied back: The helmet is suitable for ponytails and braids Forced Air Cooling Technology: Thoughtful ventilation system for optimal head temperature Efficient ventilation for this type of helmet with 4 air inlets and 4 air outlets Size adjustment through a half-ring of very durable and moldable plastic for optimal stability and fit Zoom Ace Urban: Precisely adjustable adjustment system with knob for individual customization