4920-00-091-0407 (GP530U1)
NSN 4920-00-091-0407 (NIIN 00-091-0407) is an optical transit square mount in Federal Supply Class 4920, Aircraft Maintenance And Repair Shop Specialized Equipment. Manufacturer part number GP530U1 (Northrop Grumman Systems Corporation, CAGE 26512); also referenced as 197, 2437, M197H (Brunson Instrument Company).
NIIN assigned November 1972; DEMIL A (none required); unit of issue EA (each), $142.99 gov standard price.