Guideline Eyegear Keel Sunglasses with Freestone Brown Polarized Lens, Tortoise The Guideline Keel offer wide sloped temples, gunmetal accents with rubber brow and nose pads for a dynamic look The Keel features innovative fully recyclable bio-based polymer Grilamid BTR frames Performs optimally in lower light conditions and is the perfect choice for shallow water conditions Freestone Brown Lens tint transmits a wide spectrum of colors for truer color perception and high contrast These sunglasses have a Polarized Polycarbonate Lens that offers 100% UVA/UVB protection