The Avila sunglasses from Kaenon feature Kaenon's Patented SR-91 Polarized lens technology. What's SR-91? In short, the lens has the optical clarity of glass with the light weight and impact resistance of a Polycarbonate lens. So you no longer need to choose between optical clarity and a light, impact resistance lenses. You get both with Kaenon's patented lens. Kaenon does us all a favor by labeling their lenses with a color code and light transparency. So in a G12 lens, the "G" stands for Grey and the 12 is 12% light transmission. A C28 lens is a copper colored lens with 28% light transmission (not as dark as a C12). Avila is a casual, stylish frame which embodies the company's Luxury Performance design and engineering mantra. This style features functional details such as recessed Variflex rubber nose pads for secure fit and heavy duty, non-corrosive, five-barrel stainless steel hinges for added comfort and durability.