Bell Sports Overdrive Cycling Helmet Bell's Overbrow Ventilation system actively ushers cool air over the head via intake ports on the brow of the helmet; a specially designed bridge keeps the ducting free from obstruction while the helmet's air-channel matrix works to maximize full-head ventilation The Twin Axis Gear (TAG) fit system adjusts to the head on two axes-circumferentially as standard fit systems do, but also vertically to better accommodate differences in the up/down position of the occipital lobe; for added comfort Bell has co-molded the system arms with soft rubber and positioned them higher to better accommodate eyewear &gt;In-mold polycarbonate shell bonds the helmet's microshell to its EPS foam layer to provide a sturdier, more solid helmet; the EPS foam is shot into the thin microshell cap when its in the mold-hence the name-rather than formed separately and taped on later Certifications: CPSC Bicycle and CE EN1078 Weight: 10 oz/285 g