FAST has developed three simple, easy-to-use air/fuel meters for gasoline, diesel and ethanol/methanol (E85) fuels. Available in single or dual sensor units, these meters give tuners the power to read two wide-band O2 sensors individually or average them together for maximum accuracy of the engine's air/fuel ratio reading. The FAST Air/Fuel Meters include several enhanced capabilities, including the built-in data logging capability that plays back recorded information on a lighted, full graphical display screen rather than using a laptop computer. Additional features include outputs for external data loggers, digital gauges, as well as a narrowband simulator function that allows you to feed your engine's computer a factory signal while using the wide-band sensor for air/fuel measurement.