The AutoCross Gray 2 1/8" Full sweep Air Fuel Ratio gauge, with standard matte-black performance bezel and flat glass lens, features a rugged air core movement combined with microprocessor technology for precision and durability, full sweep for increased accuracy, small 2 ⅛" hole size, push-button calibration, integrated red warning light that illuminates the entire gauge when activated, warning light output for additional indicator lights, analog .5 – 4.5VDC output for data logging systems, LED lighting options (Warm White or Cool White), a premium BOSCH wideband air/fuel sensor, a FAST™ wideband controller, installation hardware, wiring harness, and a weld-in bung with plug, calibrated for gasoline applications only (please call for additional fuel applications), and requires selection of a curved lens when choosing a Radial bezel, with a warning that it may expose users to Lead, which is known in California to cause cancer or birth defects or other reproductive harm, with more information available at www.P65Warnings.ca.gov.