Size Description: This is a small lightweight off-road helmet, S: 52-53CM, M: 54-56CM, L: 57-58CM, XL: 58-59CM Out of range is not suitable for wearing! <br><br> Helmet Size Tips<br><br> (1)Wrap a measuring tape around your head about a half-inch above eyebrows <br> (2)Take measurement two to three times to pick the largest one. <br> The helmet is the perfect choice for city and travel, with a wealth of <br>standard features and top performance in terms of comfort, size, <br>safety and functionality. The ideal helmet for people looking for <br>full-helmets with aesthetic and safety features and the practicality<br> of an open helmet. Because the streamlined chin guard fits perfectly into the outer casing, the chin bar is in the closed<br> position and the performance is full-faceted. <br> It contains S, M, L, XL inner lining, S, M, L, XL size, all can be used. The size of the helmet is mainly adjusted by the inner lining<br>