Oil Pressure, Dual, Supercharger Sump, Bendix Magnesyn, C-121 Lockheed Constellation PBY Catalina otherwise the card indicates direction

otherwise the card indicates direction given the appropriate electrical input from the remotely mounted directional gyro

or film spools

Virtually the same aircraft

in its original bakelite case

This is a lot of 6 vintage voltmeters & ammeters

Oil Pressure, Dual, Supercharger Sump, Bendix Magnesyn, C-121 Lockheed Constellation PBY Catalina otherwise the card indicates directionThis is a dual Oil Pressure indicator as used to measure oil pressure in the left and right hand supercharger sumps in the US Air Force C 121 transport version of the Lockheed Constellation. See photo of the location of the instrument on the air conditioning control panel from the C 121 flight manual dated 1965. Measures 3. 25 inches diameter and ~3 inches deep.