What's the best Ultrasonic Cavitation strength?

As the frequency Hz increases penitration of the  energy decreasea neans it acts more superficially.  In clinical terms 40000 Hz is more superficial  and concentrated  than 22000 Hz at same energy level. 40 k device are more powerful but can can causes skin burns  However nonsurgical devices of today  have limited role today for body contouring

Interesting question. US Cavitation non invasive therapies could at those very high settings cause subdermal severe burns. Only in person evaluation by the doctor offers at least some safety. Understand this technology has very limited positive results. Good Luck..