Interchangeable lens system, Spherical 8.75 base, Patented XYZ Optics, Pure Plutonite, Iridium coatings. Frame Specifications: O Matter frame, Open edge design, Metal Icon accents, Patented Unobtainium earsocks and nosepads, Engineered to fit medium faces. Available in: Dark Grey/Black Iridium, Jet Black/Black Iridium, Pearl/Black Iridium, Plasma/Gold Iridium, Black Chrome/Titanium Iridium, and Polished Aluminum/Titanium Iridium.