Funny you should ask that question today. I just hung up the phone with Sota in regard to that very question.
Saw a new ND yesterday and when she found out that my husband had been using the Silver Pulser for a year, she was concerned that it may work like the Clark zapper and asked me to check it out. Seems the zapper was known to also kill T cells, which is a bad thing. From what I can tell, the zapper ran on 30 kHz and the Sota pulser uses 3.92 Hertz and also uses different technology.
Having said that, I have to say that I have no idea what in the hell that means. If someone can explain this for the layman, I'd appreciate it.