I want to give this tremolo arm a good review, not due to any specific function, but simply because it fitted my old Yamaha Pacifica strat "copy" perfectly.
I have a Yamaha Pacifica Stratocaster copy that was purchased second hand without the tremolo arm. I did some research on internet and found this page and did a guess that the Pacifica arm was a 5M screw-in (5 mm screw) and it turned out to be the right guess. Very happy with it.