Here are some photos of the stylus how its fitted. As you know there are small hook like bits of plastic at the top of the stylus, this has to hook under the cartridge holder. I use my thumb and forefinger to make sure the stylus snaps into place, they do click! but the red ones don't seem to......
i must admit, i bought some new stylus off ebay and two of them were faulty. The 2nd VZ i bought, gave little or no sound out of one speaker, like a plank i swopped over the complete record deck from VZ 3, turns out the stylus was shot.....
so beware of stylus, the ones i have are RED, the ones that came with the VZ's are black and have a triangle logo on them, but they cleaned up ok.
STY 123 is the correct number. Ive seen expensive ones on the net, but im not sure if they will make much of a difference, my VZ's sound ok now.