Complete Wideband Air Fuel Ratio kit. White OLED Display 52mm (2 1/16"). Utilizing the latest Bosch wideband O2 sensor -5 wire heated LSU 4.9 our gauge now has the widest range 10.0:1 to 20.0:1 AFR readings on the planet. Featuring white OLED readout in the center of the gauge for AFR and a bar-graph style LED's around the outside of the gauge to display Boost. Note: The numbers do not light up by LED. Range: -30 vac. ~ 45 PSI Boost. This is a complete kit that includes everything you need: AFR digital Gauge, Optionally dim 20% with headlights on (switch wire), Bosch 4.9 5 wire heated O2 sensor, Waterproof Boost Sensor, Silicone Tubing , Weld in Bung, Instructions, Wiring harness(Gauge to O2 sensor) 10 feet long, Plug and play, Decals, Visor/hood, 0-5 volt output signal for data logging.