Ammeter, 100mA, WWII Japanese Navy Aircraft S2 Tracker 25 inches square by ~7

25 inches square by ~7

the narrower pointer which indicates airspeed in 10 km/h increments rests behind the thick pointer

Here is a Radio Magnetic Course Indicator which was used in a variety of US military aircraft of the 1950s

whichever is less

You may encounter an Astrograph among collectors

Ammeter, 100mA, WWII Japanese Navy Aircraft S2 Tracker 25 inches square by ~7This is a Japanese Ammeter, 100mA. It is presumed to be a WWII era indicator used in aircraft of the Japanese Navy judging from the anchor symbol on its face (lower left, below pointer). This has not been verified. Aircraft that may have used this have not yet been identified. It is in good condition given its age. Measures 2. 5 inches diameter and ~1. 5 inches deep. The glass and case are intact and the lettering is distinct.