Ram 1" rubber ball with a 1.25 x 10MM male thread. This will screw into the mirror mount on the FJR, Deauville NT700V, Concours and many other bikes with the same size thread. Thread length is 10.75mm long
Photos below are of the Honda Deauville NT-700V. If your mirror mount has a plastic plus in it you may be able to unscrew it or pry it out with a small screwdriver. If you must pry it out cover painted surface with 2 or 3 layers of masking tape to protect finish.