Made by Folsom Electric Company, this unit generates stimulating electrical currents which are similar in intensity and flavor to the signals put out by TENS units. These Folsom boxes have two channels instead of one, so you can use two pairs of electrodes (a total of 4) at once. The small battery compartment is accessible using a small sliding door, so you won't need a screwdriver to change it.
There are four control knobs; two knobs control one channel. For instance, the second intensity knob controls the second channel, instead of fine tuning the first one. Each channel also features a red button, which functions as a cut-off switch for that channel.
The PSG-MAX unit, shown here, differs from the basic PSG unit in two ways. First, its circuitry allows a stronger maximum output, for those who seek an extra-strength jolt. Second, the PSG-MAX has an extra switch which will allow you to turn off the pulsing feature, so that the signal is more constant, and only varies in response to your own manipulation of the intensity control.
AC adapters cannot be used with the PSG-MAX unit; they can only be used with the basic unit.
Folsom Electric Company offers a lifetime warranty on all their power boxes and accessories.