These joystick knobs have been designed specifically to fit a dynamic linx joystick controller. They will not fit any other joystyick controller.
Please refer to the picture to make sure your joystick controller has the little black plastic fins on it that indicate that it is a dynamic linx controller.
We are currently only offering the joysticks listed in this listing as an option for the dynamic linx. However if you see any other joysticks of ours that you like please let us know and we may be able to help.