Tachometer, Dual Engine, Electric, Type E-14, AN5530-2 Engines 1 & 2 Canberra It has an overhaul stamp

It has an overhaul stamp on the rear case from Naval Air Station Penscacola (FL) dated Aug 1959

The pointer floats a bit

see photos

since it has Russian Cyrillic lettering on its face

Tachometer, Dual Engine, Electric, Type E-14, AN5530-2 Engines 1 & 2 Canberra It has an overhaul stampHere is a WWII era dual engine electrical Tachometer measuring engine revs up to 4500 RPM. The Type E 14 AN5530 2, made by Friden part number 8DJ19 was used across multi engine US military aircraft during WWII, such as versions of fighters P 38 Lightning and P 61 Black Widow, medium bombers B 25 Mitchell and B 26 Marauder, and paired with one more dual tachometer for engines 3 & 4 in heavy bombers such as B 17 Flying Fortress, B 24 Liberator, and B 29