The same instrument, with appropriate shunts, can be used to measure current intensity and, on placing a large resistor in series with the coil, it becomes a voltmeter.
The one presented here is a voltmeter with 3, 150, 300 and 750 volt ranges, an internal resistance of 100 ohm/volts and a scale with 150 divisions.
It has a sturdy case of polished wood (16.5 cm x 17.5 cm x 8 cm) with a leather handle; the screw for the zero adjustment is on the bottom of the cover.
The instrument can be used horizontally and vertically; it has five terminals: one in common for the positive pole and the others for the negative poles in the different ranges.