HOTSYSTEM Electronic Voltmeter Voltage Volt Gauge Meter Blue Digital LED 2inches 52mm for Car Vehicle Auto Warning signal:Light will light up in red when voltage is lower 11.5V. Read range:Our gauge will precisely measure the output voltage of your vehicles electrical system between 6.5  15 volts. Easily display at night:Our gauge is highly visible with a blue digital LED,easy viewing at all angles during any lighting conditions. Easy installation:Our gauge includes electric wire with necessary mounting and installation hardware,no need any sensor. Note:Please make sure the voltage is upper 6.7V to litght up the gauge. Clear and bright LED Display during the night. Good looking:Add a racing look and feel to your ride Precision movement and extreme accuracy. Easy installation:Our gauge includes electric wire with necessary mounting and installation hardware,no need any sensor. Warning signal:Light will light up in red when voltage is lower 11.5V.