Electrical sensation seat/device

I came across a "hot seat" online and I would love to build one, but I cannot get any info as to the device that is used to provide the voltage with extremely low current.
Below is a picture of the seat I found. When I emailed the creator about how it was built all he would tell me was "static electricity - think Tesla".
The only think I have been able to come up with is a TENs unit, but a TENs does pulses, not constant voltage output. From the look of this seat, he has a device mounted under the seat and it is variable in intensity. Also it plugs into a wall outlet instead of being battery powered.
The way this works is the neutral is connected to the plate on the seat, and a lead is connected to something that is used to touch the person sitting on the seat. Where ever they are touched they feel the zap of the electricity flowing into them.
Any and all help, pointers, whatever is appreciated.
Thanks
Serp

 

Tesla coil - Wikipedia, the free encyclopedia

 

Not trying to be rude, but I doubt there is a Tesla coil tucked up under that seat.

 

And not to be rude either I built one for a science fair project that could easily fit under that seat. The basic power supply was a Model-T spark coil powered by eight D cells series/parallel connected. The Tesla transformer consisted of a primary made from 10 turns of #4 wire and a secondary made from a 12" long cardboard tube wound from one end to the other with one layer of #32 magnet wire. The Tesla coil could easily produce a half inch spark. There are more details some of which I have forgotten including the size of a capacitor that I think but am not sure was in series between one leg of the spark coil and the primary. The device was built horizontally and was no more the six or eight inches high and 12" wide.