Traditional incandescent lighting illuminates around the perimeter of the dial, The included Type K thermocouple assures maximum accuracy and minimum response time, AutoMeter’s race proven digital stepper motor electric instruments provide unmatched accuracy which is further increased by utilizing a self calibration sequence during power up, Gauge kit includes Type-K Thermocouple, wiring harness, various methods for thermocouple installation, bulb and socket assembly, red and green bulb covers, mounting hardware, and detailed instructions for installation, 12 and 16 volt compatible, compatible with nearly every street car or race car electrical system.