Faria Beede Instruments White 2" Fuel Level Gauge E-1/2-F Dress. 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 Dress White 2" Fuel Level Gauge E-1/2-F: Manufacturer: Faria Beede Instruments Color: White Features of Faria Beede Instruments Dress White 2" Fuel Level Gauge E-1/2-F Perimeter-lighted black dial Stylish blue and white graphics Black aluminum bezel with burnished edge Flat glass lens American and metric scales and icons Package Contents: Faria Beede Instruments Dress White 2" Fuel Level Gauge E-1/2-F Faria Beede Instruments 13101: White 2" Fuel Level Gauge E-1/2-F Dress