Ammeter/Voltmeter, WWII Japanese Aircraft Douglas It has date stamp of

It has date stamp of January 1951 and Boeing tamper evidence seals

combining directional finding and general radio signal receiving

and US Navy versions R4D 6 & 7

By rotating the sight to align with the angle of terrain travel vs the intended aircraft course

It has a screw-type heeling compensator

Ammeter/Voltmeter, WWII Japanese Aircraft Douglas It has date stamp ofThis is a Japanese Voltmeter or Ammeter. The scale is labeled to a value of 2. 0, and "2000V" is embossed in small lettering in the upper right of the dial, so we aren't sure of the exact function or application. It is presumed to be a WWII era indicator used in aircraft of the Japanese Army or Navy. This has not been verified. Aircraft that may have used this have not yet been identified. It has the "YEW" symbol of the Yokogawa Electric company on