Bell Overdrive Road Helmet 2016 Fusion In-Mold Polycarbonate Shell is the result of an in-molding process which bonds the helmet's Microshell to its EPS foam layer for a sturdier, more solid helmet 19 sweeping channeled vents bring cool air in through the front, allowing it to pass over your head and then flushes warm air out of the rear ports -- so YOU stay cool and your HEAD stays cool Overbrow Ventilation intakes work with the moto-proven Velocity Flow Ventilation system to actively cool air over the head via 4 ports on the brow of the helmet CoolMax padding moves perspiration away from the head for cool comfort Twin Axis Gear fit system adjusts to the head on 2 axes -- circumferentially as standard fit systems do, but also vertically to better accommodate differences in the up-down position of the occipital lope