This is the gold standard of car audio volt meters. With an ultra fast response time and a digital read-out, you're getting the most accurate information possible about your car electrical system.

The premium version has a min hold function and a dimmer function. The min hold function is to allow you to see the lowest voltage your system is hitting.  The extremely fast sampling and refresh rate can make it difficult to actually see the minimum voltage with the naked eye, and that's what the min hold function helps with.  The dimmer function is to allow you to adjust the screen brightness to whether it is day time or night time. This makes the volt meter less harsh on the eyes at night. The regular version does not have either of these functions.

To connect the meter your system, connect the black wire to ground, the white wire to remote, and the red wire directly to whatever positive wire you care most about monitoring. Whether that's your alternator, amplifier, or rear battery bank, this will give you the most accurate reading at that point. Approximately 40,000 samples per second are fed into an average that's then displayed to the screen for a super accurate real time read-out.

Specs:

Stand-by current                          0     uA

Max Operating current                  0.45 uA

Typical Operating current              0.37 uA

Operating Voltage                       7-20V

Sample Rate                            ~40,000/s (AKA really fast)

Mounting Flange Dimensions       W: 2.375" (60mm) H: 1.875" (47.5mm)

Case Dimensions                       W: 2.050" (52mm) H: 1.58" (40.5mm) D: 0.555" (14mm)