The SoundQubed Voltage Gauge is great for monitoring at the source. The VM-1 reads DC (Direct Current) voltage from your battery or direct from your amplifier to give you real time peace of mind. The VM-1 uses a 12 bit analog-to-digital converter for the most precise readings and offers a 'Lo' and 'High' voltage warning flash that tells you when you are reaching critical voltage limits. The SQ VM-1 comes with a green back lit display with SoundQubed etched into the top of it. This gauge is guaranteed to save you time and money and offers multiple mounting options.