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 5920-01-198-8821
NSN 5895-01-014-0438
NSN 5930-00-803-1393
NSN 2925-00-902-3881
NSN 6320-01-459-6992
NSN 5835-01-171-0258
NSN 5996-00-525-1777
NSN 6135-01-400-2947
NSN 5915-01-264-8120
NSN 5998-01-479-0287
NSN 5960-01-391-8860
NSN 6135-00-686-4777