EPR gauge as found within the main instrument panel of various classic aircraft. Tristar / B747 / B737 to name some possible uses.
The unit is in good condition including the rear canon plug. This is a real aircraft gauge from the classic era of aviation. The unit has not been powered (apart from a working bug) and any attempts to do so are at your own risk but the unit would make a great addition to your simulator or it could be a starting point for you own project.