Wow!
I just saw the video 6 or 7 times. I have had a monobolo from Taiwan that looks just like that (so I guess it is a Kongzhu) for many years and I cannot do those tricks (haven't used much, though).
They are wrapping the monobolo like a top not a diabolo. By that I mean that a right handed player will make it spin counter-clockwise. I had always done it the reverse, so with the string untwisted the "head" pointed away from me. But in the other way it can be played like a top.
Bam! (that's me hitting my forehead).
The main trick they do with the smaller one are half-orbits. When the guy throws it in the air he is doing lasso catches. Ok, I NEED to learn this before the end of the year!
The bigger one doesn't seem to tilt when it is not spinning, so I guess it is counter-weighted enough to be a diabolo in disguise.
How loud they are! Much louder than mine.