6685-00-641-6800 (MS3397-17)
NSN 6685-00-641-6800 (NIIN 00-641-6800) is a plug humidity indicator in Federal Supply Class 6685, Pressure, Temperature, And Humidity Measuring And Controlling Instruments — an item which uses the changing color of a desiccant in the presence of moisture to indicate humidity. Manufacturer part number MS3397-17 (Military Standards, CAGE 96906); also referenced as MILP6131 (Military Specifications); 115 (Driaire Inc).
Key specs: refillable; full characteristics table below. NIIN assigned January 1963; DEMIL A (none required); export Schedule B 9025.80.5050; ships at 0.004 lb / 0 cu ft.