For instant readout of present voltage and current in a system, this current meter fits the nerd. Did I say "nerd"? Meant "need". Really.
Originally designed with automotive use in mind, this dual panel-mount meter has a hefty 0-100VDC and 0-9.99A range. It's not self-powered, meaning you have to apply a separate 3.5-30VDC to power this meter. Not exactly precision instrumentation here, but it's good enough to make sure you're not abusing your DC power system.
The heavy wires are wired in series with your loaed (up to 3A, unless directly soldered to connections), and the thinner wires are your meter power (red + and black gnd, 35VDC MAXIMUM), with the yellow wire as your voltage measurement.
Note: If you expect to exceed measuring 6A, please directly solder the wires to the meter.