Costa Del Mar Loreto Sunglasses Made in US Case included Lenses are prescription ready (rx-able) Costa's most high tech lens - 580 Glass provides superior clarity, scratch-proof, 100% UV protection and the best polarizing efficiency available. Blue Mirror Polarized is best for bright, full-sun situations on the open water and offshore. Costa uses only the best in metals Monel is a super tough, corrosion-resistant alloy that provides a different look and feel. Comfortable M fit. Built by hand and backed for life. Every pair of Costa Sunglasses includes a limited lifetime warranty.