Interchangeable Series: Flexible, TR-90 nylon makes up the interchangeable series. Shatterproof polycarbonate lenses provide no nonsense reliability, shielding your eyes from almost anything hurled at them. Multiple packages give you the option of different lens combinations in changing light and weather conditions. Using Socket™ technology, the frames are built to surround the eye orbits, preventing wind, debris, and shadows form disturbing your field of vision. Each frame is desired to cut wind and eliminate backlit glare. Our unique Slot™ design forms the Interchangeable system, providing customs grooves in the frame, making the interchanging of lenses hassle free.