| Module A-175 (Dual Voltage Inverter) is exactly what it says it is: two identical inverters, which will take a voltage and output it in an inverted form - so that an input of +5 V will be output as -5 V, an input of -2 V will be output as +2 V, and so on.
Two LEDs give a visual indication of the (positive or negative) output signal.
> tech specs
Width: 4 TE / 4 HP / 20.0 mm
Depth: 35 mm (measured from the rear side of the front panel)
Current: 20 mA