Running too lean while enjoying spirited driving in your vehicle is one of the leading causes of expensive engine damage. AutoMeter's Narrowband Air/Fuel Gauges pair with older Oxygen Sensors to warn of lean burn conditions under heavy engine load. Connects directly to the factory O2 sensor on many applications, or uses the AutoMeter 2244 Narrowband O2 sensor. Not compatible with 5 wire air/fuel sensors.Features: Compatible with factory narrowband O2 sensors (0-1V) May require model 2244 if the vehicle does not have a factory narrowband primary O2 sensor Features LED radial bar graph display (gauge does not have provision for backlight) Will not work with wideband O2 sensors (0-5V) - please check your specific application before purchase Product Description: 2-1/16" Narrowband Air/Fuel Ratio Gauge, Lean-Rich, Ultra-LitePit Stop USA offers Auto Meter Ultra-Lite Electric Air Fuel Ratio Gauge - 2-1/16 in. 4375 at low everyday prices. Be sure to check out all our products from Auto Meter including Auto Meter Digital Air / Fuel Ratio Gauges.