The Thundervolt zapper is NOTHING like LloydS Quad zapper. A Thundervolt uses two handholds and two footpads; total of four. The Lloyds unit has only has two.
A Thundervolt uses two opposing waveforms with four frequencies. The fourth frequency is opposing and not combined with the other three.
A Thundervolt's fourth frequency is like a Rife machine; it may start oscillating at 300,000 Hertz and work down to 10,000 in seven minutes, depending on the condition of the user. This affords a very wide window to kill thousands of different parasites all at once.
The 4 outputs of a Thundervolt are totally interchangeable, giving the user 12 options of mix and match energies from the four frequencies.
A four gang switch would be cost prohibitive, and would not fit in a Thundervolt box.
A Thundervolt zapper can deliver 300,003 frequencies or more and is $123. less than a Harmonic Quad 5 zapper.