Louis Garneau Diamond II Road Bicycle Helmet. When it comes to staying cool on the bike, your Bicycle Helmet needs the proper amount of vents or you'll overheat and fast. The Louis Garneau Diamond II Road Bicycle Helmet features a whopping 40 vents, including 8 front Venturi Vents for maximum ventilation. Ventilation is one matter, but what about construction The Diamond II features Garneau's patented Super MSB Monocoque Structural Base and EXI technologies. The monocoque polycarbonate base acts like an exo skeleton providing more than a fashion statement or protection against abrasion for the base of the Bicycle Helmet: it is one of the strongest ways to achieve structural strength. Instead of using internal rib cages which add more weight and limit the number of vents, they used Super MSB and EXI technologies in conjunction. This consists of 2 polycarbonate bars placed inside the Bicycle Helmet at specific structural location and 9 carbon bridge inserts which provide the strength exactly where it is needed. The result: more vents, less weight.