Bell Star Pro Shield Road Bicycle Helmet. A full commitment to speed and efficiency means never having to compromise, and that's exactly the idea behind the Bell Star Pro Shield aero road Bicycle Helmet. Adaptable versatility is the hallmark of this aero Bicycle Helmet, particularly the ultra innovative Active Aero venting system which lets you regulate airflow, temperature, and aero efficiency on the fly with a simple slider mechanism integrated into the top of the Bicycle Helmet. Simply slide open to maximize ventilation on the climbs or slide shut to seal off the vents for an aero advantage on the flats or when you're sprinting for the top step of the podium. And for even more aero goodness there's an integrated and removable Magnetic Zeiss Eye Shield that increases aerodynamics as well as delivers optimal eye protection. Overbrow Ventilation further assists in cooling the head while the Float Fit retention system ensures the Bicycle Helmet's perfectly positioned with an ultra lightweight design.