6680-01-031-9660 (SIZE 4 744SIZE4)
NSN 6680-01-031-9660 (NIIN 01-031-9660) is a liquid sight indicator in Federal Supply Class 6680, Liquid And Gas Flow, Liquid Level, And Mechanical Motion Measuring Instruments — an item so designed to have a portion or all of its body transparent to permit the visual examination of the amount of liquid in a pressure vessel, boiler. Manufacturer part number SIZE 4 744SIZE4; also referenced as 744 SIZE 4 (Ernst Flow Industries).
Key specs: port seal cap; full characteristics table below. NIIN assigned December 1976; DEMIL A (none required); unit of issue EA (each), $34.14 gov standard price; export Schedule B 9026.10.7000; ships at 0.3 lb / 0.02 cu ft.