Take our ultrasonic plastic welding machine as an example. Our plastic welding machine distinguishes the frequencies of 15k and 20k from the horizontal adjustment. For example, the first blue welding head has four horizontal screws for adjustment, which are 15K, while the second and third ones are not. Obviously it is 20k, but it can be seen from the body shape that the third one is smaller than the first two. In fact, the frequency of the third picture is 35k, because our picture is also based on the actual scale.