Fuel Flow Indicator, JU-88, Verbrauchs-Anzeiger 9-2172 A-1, Luftwaffe
Here is an electric Fuel Flow Indicator (Verbrauchs-anzeiger), manufactured by LGW-Hakenfelde as used in the Luftwaffe Junkers JU-88 bomber, and possibly others. It measures the rate of fuel consumption up to 500 liters/hour.
The artifact is labeled as a war bring-back as having been extracted from a JU-88. Unfortunately, one of the mounts broke along the way. Measures ~2 inches diameter and ~3 inches deep.