With no laptop required, FAST has developed three 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 wideband 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 built-in data logging that plays back recorded information on a lighted, full-graphic display rather than a laptop. 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 wideband sensor for air/fuel measurement.