The DB killer is NOT included; it is sold separately. Pro-Race silencers design comes from the first prototypes made for MotoGP. Pro-Race silencers are built putting together a conical-shaped part (the main body of the silencer) with a cylindrical ending section (ø98mm) Titanium  The silencers are secured to the bike by means of mounts welded to the main body, their cone-shaped design provides a reduction of dimensions and weight, but it also reduces the overall volume of the exhaust, thus limitating noise damping capabilities and the application on bigger or demanding engines.