The outer shell of the Shadowmatt is made of polycarbonate, which is a material used, among other things, for high-end motorcycle helmets. It is coated with anti-scratch matte paint. The inner shell is made of variable density polystyrene providing better dissipation of the energy produced on impact. The internal comfort foam, “shape memory” type, which guarantees a constant thickness over the years of use and the semi-rigid jugular cancel all the risks of overturning the helmet in the event of a violent movement. This internal comfort foam is removable thanks to a clip system much stronger than the scratch/Velcro system. It can therefore be washed at will to be able to constantly wear a clean and scented helmet. Equipped with a front air intake, the Shadowmatt helmet provides exceptional ventilation. Fresh air is channeled from the front inlet to the rear extractors around the comfort foam that prevents sweating. This concept generates a strong internal air flow that avoids the need for visible and unsightly air inlets: equestrian elegance is maintained without banishing technicality and comfort. The size corresponds to the circumference of your head at the height of your forehead, in cm. There are 3 shell sizes available: Small (S), Medium (M) and Large (L). Each shell can accommodate different interior foams of different sizes to obtain a perfect fit to the rider's head. The small shell goes from 52cm to 56cm. The medium shell ranges from 55cm to 58cm. The large shell ranges from 57cm to 61cm. If your size is 55cm or 56cm you can choose between a Small (S) or Medium (M) shell. If your size is 57cm or 58cm you can choose between a Medium (M) or Large shell (L).