Product details:

They're compatible with 12 and 16 V systems, use quick and accurate air core metering, and have vintage incandescent lighting around the dial perimeter. These tachs are designed to combat moisture and dirt with a fully sealed bezel design, UV-resistant paint on the face and pointer, and corrosive-resistant hardware. They work with most 4-, 6-, and 8-cylinder motors, V6 outboards, and many 12 V racing ignitions. Red and green bulb covers are included for your personal preferences, along with size, color, range, and finish options.