Brown Digital Engine Instrument Monitoring System from The Boeing Co.
This item is an official digital engine instrument gauge removed from an operational Boeing 757 Main Instrument Panel. The gauge is produced by General Electric and is in the brown colour scheme and therefore may be appropriate to the B747,757,767,777 series.
The gauge is extremely rare and was used to display the Engine Pressure Ratio and Exhaust Gas Temperature of the standby engine.
The unit has not been tested and any attempts to restore to part/fully working condition would be at your own risk. The rear of the unit suggests standard 5v backlighting and 28v power.