Faria 2" Fuel Level Gauge Metric - Euro Black - 12802Faria 2" Fuel Level Gauge Metric Euro Black 12802 2" Fuel Level Gauge Metric Euro Black Hole Size: 2" 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