An item specifically designed to be used with a multiscale dial or sector of a measuring device to limit, open or close the observation of the scale (s), or dial (s) desired. it is usually flat and contains one or more observation slots. It may be hinged or otherwise moved by rotary or straight-line motion to expose the scale or scales required for observation.
NSN 5930-01-178-9623
NSN 6610-01-423-3608
NSN 6240-01-068-3491
NSN 5996-00-469-4266
NSN 4140-01-112-1729
NSN 6110-01-189-2731
NSN 6130-00-150-7294
NSN 5996-01-633-7979
NSN 5925-01-284-3381
NSN 5920-01-598-5172
NSN 6610-00-848-4764
NSN 6150-00-097-8886