In a parallel universe, not long ago, we set out to develop the ideal interchangeable sunglass. It was agreed that this style needed to be lightweight, contemporary, and performance driven. The Parallel is just that. 9 Base Lens Curvature. Frame Measurements 65-15-125. Carbonic TLT Engineered to be the most impact resistant lens material in the world. Carbonic TLT lenses are optically corrected to maximize visual clarity and object definition. TLT Optics: Tapered Lens Technology corrects light distortion for true optical clarity. Evolve Frame Material We incorporate the revolutionary, Rilsan#&174; Clear material into what has become the largest eco-friendly sunglass collection in the world. This material allows us to create lightweight, durable frames, that are over 53% bio-based. Rilsan® Clear is derived from the renewable, non-genetically modified castor plant. Evolve frames are flexible, lightweight, highly elastic, remarkably tough, and have excellent chemical resistance. Most importantly, this material is not petroleum based. Pivlock Interchangeable Lens System The Pivlock Interchangeable Lens System features a proprietary, patent-pending temple and lens interface that truly provides an unobstructed field of view. Engineered to minimize frame weight while maintaining a secure fit, both the temples and nosepiece remove easily, making the task of changing lenses easier than ever.