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 5920-01-149-9738
NSN 5920-01-200-9318
NSN 6645-00-044-7011
NSN 6145-01-543-6827
NSN 5930-01-336-5615
NSN 5996-01-397-2142
NSN 6145-01-053-2969
NSN 6650-01-623-1386
NSN 5960-01-362-3846
NSN 6145-00-275-4046
NSN 5930-01-437-9081
NSN 6240-01-384-4868