Its a 30 KHZ ocillator.
I make mine myself, from a 555 clock chip, but you can buy them already made for $25-$30 on ebay.
They destroy micro organisms by disrupting the communication in their nuclei, thus the cell dies because it cannot feed or divide. (it works for tumors too)
It was discovered by Dr. Royal Alan Rife about 80 years ago or so. It made the Med mafia so angry that they had the feds burn down his office building.
What a giant steaming pant load of quackery.