Im using the H516 holder in combination with rubber plate for C516 microphone on my accordion. I have used them on several instruments, and they always worked as they are supposed to. None of them ever broke, nor the microphone slipped out during the gig. Im always using it with the rubber plate, and never by screwing them to the instrument, so if you want to do the same and if youre buying the holder, make sure you get the rubber plate, as it doesnt come along.