GlowShift’s Black 7 Color Series Analog Wideband Air/Fuel Ratio Gauge is an essential tool for closely monitoring and fine-tuning your performance vehicle’s air-to-fuel ratios from 10 ~ 20 AFR quality values. Measuring the air-to-fuel ratio through the range of RPM and manifold pressure will result in maximized power output and engine performance. You’ll also have the classic look of an analog gauge with an illuminated red needle that sweeps 270 degrees and choice of a blue, green, yellow, purple, red, teal or white LED display on a Black gauge face.