Try this site http://adcomtronics.com/ for info on zappers... they have a Frequently Asked Questions portion... I got my zapper from them and have been using it about 6 months... Hulda Clark said to do the parasite cleanse (herbal or zapping) prior to the liver cleanse... so I got a zapper... I can't say ANYTHING one way or the other - whether it does me any good or not - I can't tell one way or the other... I believe it MUST be doing what it's supposed to, as when I did my first cleanse about a month ago, I didn't have any problems... I'm using it almost every night, as I'll be doing cleanses regularly until I'm all cleared up...