Tachometer, Dual Engine, Electric, Type E-14, AN5530-2 Engines 1 & 2
Here 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 Superfortress.
The glass, dial, and case are intact. This one has a serial number prefix of AF-45, indicating a manufacturing year of 1945. The face of the dial has a small bit of corrosion at 6:00 o'clock, but otherwise it is in fine condition for its age. Measures 3.25 inches diameter by 4.5 inches deep.