Ultrasonic Power: The most common ultrasonic power is 40 kHz, and there are many frequencies available for different applications, ranging from 25kHZ to 200 kHz. Generally, the smaller the kHZ, the larger the cavitation bubble, and the more power it packs. The larger the kHZ, the smaller the cavitation bubble. In this latter case, smaller bubbles deliver high-precision, gentle cleaning. Also note that the watts of the generator will match the watts of the transducers, as well as the kHz. One thing to consider in your decision is watts per gallon (WPG). Most tanks will be under 40 WPG, which works on low-density materials like plastic and aluminum.Conversely, when steel, cast iron and other metals are introduced into the tank, it will absorb the watts of the tank and may not clean parts as effectively. In most cases, our UltraSonic LLC tanks are 80 WPG.