Brand: K&N Engineering
The K&N Air/Fuel Monitor is designed to help with jetting or injector settings on any engine running on unleaded gasoline, alcohol, propane, or nitrous oxide. A 3-color LED gauge displays your engine's air-fuel ratio from Lean to Rich.
This round in-dash unit mounts in a two inch hole like any standard guage for a permanent, professional appearance. The gauge is designed for use with a Single-Wire Oxygen Sensor (Part No. 3882, sold separately). If your vehicle is already equipped with a one-wire oxygen sensor, you can just tap into the existing sensor wire rather than installing a separate sensor.