This mini volt gauge is similar to the two wire version we stock – with one key difference: it can be powered from a separate source from what it is monitoring. This allows the gauge to read right down to 0V without shutting off. To connect this gauge simply connect the Red wire to a positive pole on an external power source, the Black wire to the ground pole of the external power source and the ground of the circuit you are monitoring, and the Yellow wire to the point which you would like to measure voltage (see attached diagram).

There are two tabs for mounting this gauge, we find they work quite well with M3 or 4/40 hardware.