Hulda Clark s 2003 "update" was to make the bottom of the output waveform at .25 volts. Parazapper quotes her about her update but on his site he shows the output of his device at 1.8 volts. And he attributes the output negative spike he wants to eliminate as being from the 555 circuit, which it's not. It's due to the capacitive characteristic of the human body. Parazapper is such a scammer and he gets away with it because most people aren't schooled in electronics technology. Any one who tries his device will always fail at completely eliminating pathogens and then the light comes on in their head if they know how to think for themselves with reason and logic. Those that don't just assume that they did something wrong or that they are somehow a rare exception. The reverse is true, the "exception" is someone that gets well by using his device.