An aero helmet with high ventilation for everyday use This helmet is the result of 145 different prototypes, and countless trips to our wind tunnel testing centre. Like all innovations, it looks different. But every detail serves a purpose: to reduce drag. First thing you'll notice is the solid casing at the point of the forehead. This moves air over and around the helmet rather than into it, reducing instability and improving aerodynamics. You'll also notice the 28 Clima vents. These are designed to suck hot air out the back of the helmet, rather than classic ventilation filling the helmet from the front (or in lots of aero helmets, no ventilation at all). Finally, an anti-bacterial and anti-odour lining with X-staticÃƒâ€šÃ‚Â® padding cushions your head. The helmet is fully adjustable with one hand if you need to tweak it as you're riding. And the CXR Ultimate is both CE and CPSC certified, while still weighing in at just 250g (for a medium size). S: 51 56 M: 54 59 L: 57 61.