I visited their site. Shows a complete lack of understanding of zapper technology.
"Also, any single frequency note or tone produced by others above 2,000 cycles per second is not only inaudible ultrasound, but is too weak, for it cannot produce any electronic magnetic pulse or “spike”."
Funny! In my younger days, I could hear up to over 28000 Hz and still hear up to 26000 Hz. As for the pulse or spike, any frequency can do that.