I used a zapper for a long time before getting into frequency specific zapping. I also used the specific frequencies developed for eradicating nanobacteria, as developed and researched by Dr. Jeffery Sutherland. I can only tell you that it makes a HUGE difference in eradicating the nanobacteria, and zapping at the general zapping frequencies didn't do it, frequency specific zapping DID. I am not against general zapping, if you are not seriously ill. It's a great overall health and maintenance therapy, but if you are seriously ill, or want solid results, general zapping is NOT always, not often, going to bring success. I know from hard won experience. I am dealing with some pathogens still, due to interruptions in treatment, but general zapping is not nearly as effective as frequency specific zapping, and one will see that even Dr. Clark makes this clear, recommending a frequency generator (frequency specific) in many cases... For more on nanobacteria, I recommend Dr. Sutherland's frequency sets and research article posted at http://www.frequencyresearch.org ALL ill people, in fact, anyone who has EVER had a vaccination should get their NANOBACTERIA eliminated, do a frequency specific zap /treatment, and boost your immunity 4x.