Overcasters are lightweight, clip-on visors that attach to any prescription eyeglass or sunglass frame in seconds, flip up instantly for the perfect instrument-to-visual transition, and when flipped down create a near perfect "simulated instrument" condition including an offset cutout to help block the view out of the window .Overcasters clip into any Airport/Facility Directory, Flight Guide or approach binder for easy storage, and can be attached and in use in seconds. Their dark plastic lenses make "cheating" difficult in the cockpit, and are manufactured for flexibility and durability. And perhaps best of all, Overcasters are widely accepted by FAA examiners for use in practical tests and checkrides.