For 12 or 24 volt power system. In surface mount box. You can't see that range with analog pointer meters. Digital ammeter shows small item power usage for lights and electronics, as well as high power battery charger and inverter current. Meter kit includes the shunt.
Tiny wires connect meter to shunt so meter can mount remote if desired.
Runs on 12 or 24 volt just 8 milliamps. Indicates amperes charging or DC usage. No installation, just plugs into an AC outlet. Not accurate for most inverter waveforms. This is important for checking battery condition, with tiny variations between some cells.