Pilot Director Indicator as used with C-1 Autopilot, WWII B-29, B-24. B-17 Dinah Reconaissance as used in the German

as used in the German Luftwaffe aircraft Me109 G-K

The lens appears to be a plastic material

including a diagram of this specific indicator

including any USN versions of the above such as the PB4Y Patrol Bomber

this indicator appears to have a production year of 1937 (3768/37)

Pilot Director Indicator as used with C-1 Autopilot, WWII B-29, B-24. B-17 Dinah Reconaissance as used in the GermanThe Pilot Director Indicator (PDI) was used during WWII in bombers of the US Army Air Force, including heavy bombers B 17 Flying Fortress, B 24 Liberator, and B 29 Superfortress and medium bombers B 25 Mitchell and B 26 Marauder, and US Navy's PBY5A Catalina and PB4Y Privateer. The PDI was located on the pilots instrument panel, and received signals from the bombardier to indicate his desired course changes, left or right, to obtain an accurate bomb