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 6240-00-287-1988
NSN 6150-00-202-9150
NSN 5925-00-137-1130
NSN 6220-00-009-6099
NSN 5985-01-206-3121
NSN 7035-01-177-2807
NSN 5945-01-255-3225
NSN 6135-00-451-0709
NSN 5975-00-953-4568
NSN 5855-00-089-3974
NSN 7035-00-797-2635
NSN 6135-00-416-2898