Fisherman Eyewear Gunmetal Semi-Rimless Frame Mantis Bifocal +2.0 Guideline Sunglass Pro Polycarbonate Lenses, lightweight, optical-quality clarity, shatter-resistant Frames designed for all day comfort, with lens tints for optimized light transmission for glare elimination. spring hinge design that reduces temple pressure for comfort fit aluminum-magnesium rimless metal frame is extra strong and durable, curved for complete face fit Polarized, perfect optical clarity and 100% UV A& B protection in the most demanding light conditions.