It is explained here:How does that generator produce H2?
No explanation whatsoever makes me skeptical.
Solid Polymer Electrolysis(SPE) & Proton Exchange Membrane(PEM) Technology - Life Giving Store
It has been tested and you are welcome to test it yourself. Chlorine and ozone are expelled into the waste chamber at the bottom of the unit.And what guarantee is there that it doesn't create chlorine and ozone?