David, Jan Volcker made me a good 27v godzilla with meter. You will have to turn dial off then flick the switch to change polarity every few minutes depending on time you want machine to work on you. I like it as it does not cause flashes in my eyes. I also removed two batteries so i work on 9 volts only. The machines that change polarity automatically gives flashes to the eyes. Here is his email address: lig...@theledman.net Take care. Melly
