ive got one on my r33 (was on their when i purchsed it)
if you get the remote controlled one, youll find it buggers up after a while, the battery connection for the remote suck, comes loose and youll find it hard to adjust the valve inside.
i've left mine open, cant be bothered with the remote any more, they do go quite though when shut, for long drives to have no drone makes for a good drive after a while
good luck either way