A cylindrical item having an internally flanged diameter designed to retain a lens or window in the objective end, or a diopter scale at the viewing end of an optical instrument. It may have one or more of the following characteristics: internal thread or machined for a press fit, method of securing, and/or knurled periphery. For externally threaded items, see retainer, optical element. Excludes cell, optical element; nut, plain knurled; nut, plain round; and ring, retaining.
Classification: Military equipments not identified by kind
NSN 5975-01-371-8820
NSN 4140-00-225-8586
NSN 5920-00-302-5168
NSN 6620-01-448-8926
NSN 5920-01-025-1618
NSN 6130-01-236-9892
NSN 6620-01-568-9203
NSN 6620-00-851-1487
NSN 5975-00-272-1231
NSN 5996-01-518-4674
NSN 6145-00-610-2283
NSN 5905-01-437-8343