Cylinder Head Temperature Indicator Dual Engine Type B-11 WWII P-38, B-25, B-26

This is an exceptional example of a Cylinder Head Temperature Indicator, Type B-11, for dual engine aircraft of the US Army Air Corps during WWII.  The indicator displayed cylinder head temperature for left and right engines simultaneously, from 0-350 deg C via dual thermocouple.  The letters AC US ARMY are embossed on its face, and the data label shows a serial number prefix of AC 42, evidence of a manufacturing year of 1942.  

The B-11 indicator was used across all Air Corps dual engine aircraft, such as the fighter P-38 medium bombers B-25 and B-26, and transports C-46 and C-47.  See photo of spec sheet and the B-25 instrument panel showing the location of the indicator. 

The dial and glass are clear and intact.  Measures 3.25 inches diameter and ~3 inches deep.