The Velocis is Bontrager's pro-level race helmet that combines safety, fit and comfort in an amazingly light package. The in-mold composite exoskeleton increases structural integrity and actually allows for more and bigger vents. Fit and comfort are one in the same, to that end, you've got the HeadMaster II fit system, which adjusts by height and circumference perfectly with one hand. The FormFit flexible brow band gives you a custom fit and improves ventilation along with recessed internal channels that manage airflow. The wicking fit pads are naturally antimicrobial and you're equipped with the ingenious detachable NeoVisor. - Small = 52-56cm - Medium = 54-60cm - Large = 58-63cm