The MOD7 Helmet from Oakley is an integrated helmet-goggle (visor) combination that delivers top-of-the-line performance in both areas. The helmet itself is built around Oakley's Skull Matrix, a combination of BOA® and MIPS® technologies that brings the rotational-impact protection of MIPS and the easy micro-adjustability of BOA together into a single system. It's built with their extra-strong Dura-Matter construction, resulting a shell that holds up to dents and dings like a true champ. The visor is made with Oakley's Prizm™ Lens technology, providing a clear and well-defined view of the contours in the terrain around you. It can also be brought closer to your face, for the most unobstructed view possible. When not in use, the visor can easily be removed via a button and placed on top of the helmet like you would with a pair of goggles. The best of Oakley's headgear is all here, contained in a single package. Oakley's MOD7 Helmet is a true integrated system experience. SIZE CHART ADULT SUPER FIT SIZE CIRCUMFERENCE S 51 - 55 cm M 55 - 59 cm L 59 - 61 cm XL 61 - 63 cm