Most people, myself included, had paid attention only to the capacitance of the testatika magnets as involving the space between the legs of the magnets. In fact, the majority of the capacitance comes from the electric field involving the body of the magnet and only a little from the electric field between the legs of the magnets.
The following measurements were made with steel magnets to demonstrate this.
In the 3kW testatika machine there are what appear to be clear plastic blocks between the legs. The following shows that if the blocks are just plexiglass then their contribution to the overall capacitance is still small. The majority of the eletric field interaction is still with the magnet material. Note that there are no such blocks between the legs of the dual disk small machine's magnets.
Note that the above may be incorrect for the 3kW machine if the blocks are something other than plain plastic and that have a high permitivity.