Zoggs Predator Flex Reactor Ultra Photo Chromatic Ultra lenses automatically adjust from a light copper lens to a dark copper shade based on the lighting conditions. The 180 degree vision is perfect for open water swimming and Fogbuster anti-fog keeps the lenses clear. The 4 Flexpoint Technology Frame flexes in 4 key areas to easily seal to your face Fitting is as simple as pulling the two straps to tighten and lifting the lever to loosen the fit.