Company item name--square, optical thru
No other part numbers with same form, fit, and function found.
NSN 6105-01-634-0322
NSN 6240-00-952-0099
NSN 2925-01-497-7055
NSN 5855-01-291-4763
NSN 5925-01-322-2046
NSN 6150-00-430-0651
NSN 6130-00-317-3054
NSN 5935-00-375-5189
NSN 6110-00-982-9714
NSN 5910-00-411-8832
NSN 2925-00-149-0760
NSN 5960-01-292-0027