The Hulda Clark zapper is a device invented by Dr. Hulda Clark. It is designed to kill parasites, bacteria, viruses, molds and fungi electrically. Viruses and bacteria are said to disappear in three minutes; tapeworm stages, flukes, roundworms in five; and mites in seven.

A battery-operated, positive offset with a very low voltage from 5 to 10 volts is sufficient. It kills parasites and bacteria wherever the current reaches them. But it does not reach the eyes, the appendix, the testes, or the inner ear bones. The current travels along the stomach or intestinal wall, not through its content.  It does not reach into the gallstones or into the living cells. The current does not pass uniformly through the body. With regular zapping, the current passes mainly through our liquids, i.e., our lymphatic and vascular system. A small fraction reaches every organ and tissue of our body. Blood and lymph are the most important locations to zap. 

Hulda Clark Zappers generate positive offset frequencies, square-wave, battery-operated. This is said to kill all bacteria, viruses, and parasites simultaneously, given sufficient voltage (5 to 10 volts), duration (seven minutes), and frequency (anything from 10 Hz to 500,000 Hz)

Dr. Hulda Clark describes how certain parasites affect our health and how we can improve our health by killing them using a parasite zapper. Since her book was first published, many individuals have claimed that Hulda Clark Zappers really do work.