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 5915-01-504-6581
NSN 5915-01-630-5962
NSN 6150-01-359-1253
NSN 6610-00-186-9180
NSN 6240-01-425-1939
NSN 5935-01-512-8747
NSN 4140-01-518-6956
NSN 6620-01-589-2857
NSN 6240-01-480-2448
NSN 6645-00-234-7223
NSN 4140-01-150-0740
NSN 6105-01-143-4877