ASA Overcasters are lightweight, clip-on frosted visors that attach to any prescription eyeglass or sunglass frame in seconds. When flipped up they instantly provide for the perfect instrument-to-visual transition, and when flipped down create a near perfect "simulated instrument" condition.ASA Overcasters clip into any Airport/Facility Directory, Flight Guide or approach binder for easy storage, and can be attached for use in seconds. Their frosted 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