The Holley Universal Gauges are 2-1/16" diameter gauges designed specifically for use with the Avenger, HP and Dominator EFI systems. They feature a blue numeric LED display as well as a 40 segment multi-color LED bar around the outside of the gauge. They require power and ground but are wired to a single wire output from the ECU for simple wiring and can be connected to the vehicle headlight switch to allow dimming for better night time viewing. Each gauge can easily be individually programmed for 44 different specific functions/operations eliminating the need for other gauges and expensive dedicated sending units. A "decal sheet" is provided with the most common inputs used so the gauges can be correctly labeled.