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 5960-00-256-0577
NSN 5910-01-158-6870
NSN 5925-01-605-5962
NSN 6685-01-044-5044
NSN 6240-01-126-9167
NSN 2925-01-629-9416
NSN 5975-01-417-1752
NSN 6610-00-587-3260
NSN 6110-00-376-4834
NSN 6620-00-185-1671
NSN 5985-01-634-0635
NSN 5930-01-234-2337