Voltmeter, 15V, WWII Japanese Aircraft Martin as used in large aircraft

as used in large aircraft in both British military and civil service during the 1950's in Reconnaissance/Bomber aircraft such as the Avro Shackleton and English Electric Canberra

such as the F-86 Sabrejet

Pressure Indicator

At almost 200 pages

which would likely be determined by the type of aircraft to be refueled on a mission

Voltmeter, 15V, WWII Japanese Aircraft Martin as used in large aircraftThis is a Japanese Voltmeter,15V. 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 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.