Faria Beede Instruments Black 2" Fuel Level Gauge E-1/2-F Euro. 0625" (53mm) Fuel Level gauge operates by sending a low amperage current through the gauges's meter to ground via a sending unit with variable resistance. The resistance of the sending units increase or decrease with the changes in pressure temperature etc... As the sender's resistance varies the amount of current allowed to flow through it to ground changes and the meter deflects showing the level of fuel. Specifications for Faria Beede Instruments Euro Black 2" Fuel Level Gauge E-1/2-F: Manufacturer: Faria Beede Instruments Color: Black Features of Faria Beede Instruments Euro Black 2" Fuel Level Gauge E-1/2-F Bold white graphics Black aluminum bezel Contoured white pointer Flat glass lens Package Contents: Faria Beede Instruments Euro Black 2" Fuel Level Gauge E-1/2-F Faria Beede Instruments 12801: Black 2" Fuel Level Gauge E-1/2-F Euro