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 6620-01-225-2818
NSN 5960-01-428-7300
NSN 6240-01-552-1995
NSN 5925-01-586-9412
NSN 6240-01-370-5242
NSN 5910-01-445-4678
NSN 6610-01-215-8489
NSN 2925-01-115-0306
NSN 5945-01-331-0591
NSN 5920-01-365-0420
NSN 5930-00-736-9753
NSN 4140-01-173-3960