Simple Three Wire Installation. Works Where Copper/Stainless Steel Tubing Will Not. Ultimate High Performance Dial Face Look. Precision Movement And Extreme Accuracy. 1 Year Limited Warranty. Traditional Incandescent Lighting Illuminates Perimeter Of Dial. 12 And 16 Volt Compatible. Incl. Bulb; Socket Assembly; Red/Green Bulb Covers. Incl. Mounting Hardware/Installation Instructions. Air-Core Electric Instrument Provide Quick And Accurate Readings.