Open on the left, closed on the right.

Italian helmet maker KASK has launched itself into the aero road fray with the new 270-gram, $360 Infinity model. Tour de France viewers will have already seen these new lids adorning the heads of Team Sky, including Chris Froome. The current yellow jersey holder opted for a traditional helmet during the two days in the Pyrenees, but was sporting the aero model during the very flat stage 11 run to Tours.

The calling card of the Infinity is that it can be switched from vents open (max ventilation) to vents closed (max aero efficiency) on the fly on the bike. And even when the helmet's vents are fully closed, there is still some ventilation thanks to two internal airflow channels that are fed by two frontal openings. Air enters the helmet from the front and flows through the internal channels, then exits from the rear exhaust ports. Vents open or close by adjusting an aerator that's situated on the top of the helmet.

The Infinity traces its lineage to KASK's Bambino time trial helmet. Both have rounded profiles ensuring that there are no sharp edges or angles to interfere with clean air flow. The Infinity comes in two sizes: Medium (48cm-58cm) and Large (59cm-62cm). It will be available in the U.S. starting January 2014.