If your local constabulary looks for the EU approval stamp, probably not. But if you purchase the version with the cat, it might be.... Check the Akro site, it shows that most of their systems are not "street legal" although most tend to ignore that at their own peril. I suppose worst case if you get pulled is to slip the stocker back on.
Here they say their slip on is "EC type approval" whatever that might mean.
http://www.akrapovic.com/motorcycle-...on-1f8573ef88/