Searchlight Azimuth-Elevation Indicator ID-277/AVQ-2, S2 Tracker, P2V Neptune
This is a Searchlight Azimuth/Elevation Indicator type ID-277/AVQ-2 as used in the Cold War era antisubmarine aircraft Lockheed P2V Neptune and Grumman S-2 Tracker, and Martin P5M Marlin Floatplane of the US Navy. The crewman or co-pilot operated a handgrip to adjust the aim of the externally mounted searchlight, and the azimuth and elevation of the searchlight's beam relative to the position of the aircraft would appear on the indicator. See illustration of the S-2E Tracker instrument panel from its Flight Manual showing the location of the indicator. Measures 3.25 in diameter and ~7in deep.
It is clearly 'experienced' but the dial markings are clear and the glass and case are intact. The yellow symbol of Naval Air Station Alameda (CA) is stamped on its side, but the stamped service date is illegible. See photos.