Costa's 580 Polycarbonate provides high clarity, impact- and scratch-resistance along with lightweight all day wear-ability. Green Mirror Polarized enhances vision and contrast, great for fishing inshore and on flats. Costa's co-injected bio-based nylon frame material is both tough and durable, while offering a comfortable fit. 100% polarization kills reflected glare and reduces eye strain. Built by hand and backed for life. Every pair of Costa Sunglasses includes a limited lifetime warranty.