Limar AirSpeed Aero Road Helmet improves your aerodynamic profile while offering exceptional ventilation. Limar Air Speed is designed for the road to give advantage while racing. Testing done at the Magny Cours wind tunnel facility in France reveals the Limar Air Speed Road helmet is as aerodynamic as a full-fledged time trial helmet without compromising ventilation. Compared to other road helmets, there is a notable difference in the coefficient of drag so you're more aerodynamic on the bike! Available in Medium (53-56 cm) weight 239 g or Large (57-61 cm) weight 275 g.