The AEM Digital Voltmeter Gauge combines unsurpassed accuracy, speed and control with an easy-to-read digital LED interface that displays voltage in 1 volt increments, and a sweeping LED "needle" that lines the edge and moves as voltage changes from 8 to 18v. The digital voltmeter gauge's digital readout will automatically increase and decrease in intensity due to the built in ambient light sensing photocell. Each gauge includes interchangeable silver and black bezels and black and white faceplates to personalize the look of your gauge. 8-18 Volts