The 909 Speedsters have a unique blend of performance, sound, and style. Like all of Cobra’s Speedsters, these feature the PowerPort cross over which delivers class-leading power; which is a critical feature when using such a short system. Uses the same internal construction as Cobra’s short RPT system so you also enjoy the same premium sound. Rolled tips give a brawny look that is matched by the sound. Mufflers expand from 3″ at the front to 3-1/2″ at the rear..