i think its just plugs into your cdi, then your origional plug that used to go into the cdi plugs into the m-max (i think). if there limited to 111mph ten mine wont even be touching the limiter as it doesn't reach that, but with the extra revs that im after i thnk it would. and on the m-max site it says that it lets the engine rev al the way through the redline, wich mine doesnt even reach at the moment lol