Stopwatch, Type A-8, Navigation Watch for Ground Speed 1942 "Jitterbug" F-89 The rotating horizon requires the

The rotating horizon requires the right electrical input to turn

The illuminating lamp is present under the center top screw

it expands in the wide part of the tube

See photo of spec sheet and the B-25 instrument panel showing the location of the indicator

Stopwatch, Type A-8, Navigation Watch for Ground Speed 1942 "Jitterbug" F-89 The rotating horizon requires theHere is an authentic WWII era aircraft navigator's Watch, Navigation (Ground Speed) Stopwatch, Type A 8, made by Elgin to Air Corps US Army spec #94 27749. With a serial # AC42 670, indicating manufacturing year of 1942. Type A 8 stopwatches were used in any WWII aircraft with a navigator, such as heavy (B 17, B 24, B 29) and medium bombers (B 25, B 26) and large transports (C 46, C 47, C 54). The outer ring of the dial counts up to 10 seconds and the