The Costa Del Mar Ballast is a sporty rimless frame, perfectly lightweight to go unnoticed when out on the water. Costa Del Mar Ballast frames are all hand-assembled. Integral stainless steel hinges Lens color options include: gray, amber, copper, blue mirror, green mirror silver mirror Costa offers four superior lens materials: Costa 400P - Plastic These lenses have earned a reputation for being impact- and scratch-resistant. They are made to handle the harsh environments all outdoorsmen face every day. Costa 400G- Lightwave™ Glass These are the polarized lenses that put Costa on the map and they still outperform the competition. They are 22% lighter and 20% thinner than the average polarized glass. Costa 580P - Plastic These C-Wall™-coated lenses are lightweight, impact-and scratch-resistant and polarized. They outperform every other lens in its class with U.S. Patent 7,506,977. Costa 580G - Lightwave™ Glass This is Costa's most hi-tech polarized lens and it's 20% thinnner and 22% lighter than average polarized glass.