For $160 why don't you just get a Throttlemeister which is about $30 less? For one thing, with the TM you can adjust it as you ride, for more/less throttle as the road situation requires. With this thing, I don't see how it's possible to do that. I'd be a little leery of something that latches onto something else. Not really clear how it works.
Sorta looks like a version of the Vista-Cruise things from back when (I dunno, may still be around).