Ultrasonic is sound generated above human audible level. In real life, high pitch sound is created by high frequency, and alternatively, the low and base tone is created by low frequency. Frequencies above 16 kHz in general are being considered as ultrasonic. Typical ultrasonic frequencies used for cleaning purpose are from 20 kHz to 80 kHz. High Power Transducer for Superior Cleaning Results Large Tank Capacity for Professional Cleaning Isolated-Circuit Design, Keep Water Away for Enhanced Safety First Ultrasonic Cleaner to Introduce Cooling Fan for Prolonged Operation.