The ZAPPER is a microprocessor-controlled device for precise and long-term frequency generation. It produces a pulsed square wave signal with positive offset. 

The Zapper by Dr. Hulda Clark, developed this technology for killing viruses, bacteria and parasites. 

Warning: In one case, a patient with a cardiac pacemaker suffered arrhythmias as a side effect of her "Zapper". Also Not recommended for Prengnant women.