Voltmeter, 15V, WWII Japanese Aircraft Martin which would likely be determined

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

such as the F-86 Sabrejet

which rotates the checklist around a vertical axis

likely to allow illumination from a light source mounted internally in the dashboard

At almost 200 pages

Voltmeter, 15V, WWII Japanese Aircraft Martin which would likely be determinedThis 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.