Hi Fechter. The Wuxing S29X-DX is a motorcycle-style throttle with a half-length rotating barrel section. A half-length rubber grip (fixed to the bar end) completes the hand-grip. Similar to some twist-grip-operated chain gear changers.
It has 3 LEDs, red, amber & green, plus a green push-button. The case has '24V' printed on it.
The green push-button is a make contact switch on the yellow and brown wires, and apparently isolated from the other wires. This just leaves the black, red, green & white wires. Woo-hoo, the fog is thinning.
I was led to believe that the pot was a 'real' pot (rather than a hall-effect device), but ohm-meter tests do not confirm this. I will set up a current-limited power-supply test. I have heard that hall-effect throttles go off to Hall Heaven very easily.