Gunmetal with Green Mirror Lens Some people bleed saltwater. These are their sunglasses. These beauties are true high-performance equipment, using integral hinges, no-slip Hydrolite temples and co-injected, co-moulding technology to deliver comfort and fit that lets you focus on dragging fish into the boat. Costa's co-injected bio-based nylon frame material is both tough and durable, while offering a comfortable fit. TR-90 nylon is a premier material for sports and performance frames as it is resistant to heat and cold. Though it is flexible, it is still durable. Nylon is easily moulded into Costa's iconic wraparound shape. Costa's most high tech lens - glass provides the most superior clarity. Costa's encapsulated mirrors (between layers of the glass) are scratch-proof. Costa's glass lens is 20% thinner and 22% lighter than the industry's average polarised glass lens while still blocking 99.9% of glare. Polycarbonate is the lightest and most durable lens material option. Providing high clarity, impact resistance and light weight all day wear-ability. The C-WALL molecular bonded mirrors provide the most scratch-resistant and smudge-free barrier, repelling water, oil, and sweat for easier cleaning. Polarised lenses are essential for anyone who spends time outdoors - especially on the water. But, not all polarised sunglasses are created equal. Costa is 99.9% polarised, providing the best efficiency available so that reflective glare is blocked-reducing eye strain and headaches. Costa's mirrors are more than an aesthetic and a necessity in harsh sunlight. Made through a high-tech ion beam deposition process, these multilayered thin film coatings make for the most scratch-resistant mirrors out there.