Traditional incandescent lighting illuminates the front of the dial. 12 and 16 volt compatible well-suited with nearly every street car or race car electrical system. Autometers Race Proven Air-Core Electric Tachometers Provide Quick And Accurate Readings With A Needle So Responsive It Can Go From 0 - Full Scale In 333 Milliseconds. Compatible with most 4 6 and 8 cylinder engines (2 - 4 pulse per revolution ignition signals) with points electronic and most 12V high-performance racing ignitions.. Optimize Use Of Your Engines Power Band And Improve Vehicle Run Performance And Driver Gear Changes With A Rapid Response High Visibility User-Programmable Shift Light.