Fuel Filler Cap, BF 109 FW 190 Luftwaffe BT-12 The indicator essentially is measuring

The indicator essentially is measuring differential pressure in the fuel line/tank

see image of instrument panel from the F6F flight manual dated 1944 showing the location of this indicator

was a component of the SCR-280-A Radio Compass System

This example is in good cosmetic condition and functions as it should

this API Computer has a modification date of 1955 and a service date of 1965

Fuel Filler Cap, BF 109 FW 190 Luftwaffe BT-12 The indicator essentially is measuringWe have been advised that this is a WWII era Fuel Filler Cap for the Luftwaffe's Messerschmidt Bf109 Fighter, and also used on the Focke Wulf Fw190 Fighter. Manufactured by Deutche Benzin Uhrin, stamped "DBU", "Kraftstoff" (fuel), and "Beluftungsventil" (vented). The corrosion is evidence of its age, but it is in reasonable condition for such an artifact. Measures ~3 inches diameter, ~5 inches across, and ~1. 5 inches deep.