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 5965-01-306-6527
NSN 5975-01-528-7886
NSN 6620-01-549-6653
NSN 6685-00-104-9626
NSN 5985-01-411-5975
NSN 5996-01-555-7690
NSN 5930-01-053-4315
NSN 5945-00-362-7192
NSN 6145-01-394-3122
NSN 5945-01-409-2718
NSN 5998-00-811-8880
NSN 5950-01-166-1025