Nothing as yet for your model 660 only the twin muffler model.
Without a bike no-one can develop a muffler.
Unfortunately I've had several guys even ask about the Serato, yet when I offered, but needed their Muffler as a template they never got back to me.
Originally Posted by Edge
Hi I need to know if you do a system for the 660 tenere need to get rid of that ugly heavy thing under the back.