Seen here is the SLP PowerFlo X-pipe and PowerFlo mufflers (SLP's quietest) next to the stock X-pipe and mid-muffler. The PowerFlo X can be used with any of the three SLP mufflers. Better exhaust flow, and less restriction and weight, means more power and lower ET's. This adds up to a great sounding exhaust that won't set off alarms. The complete PowerFlo exhaust features four mufflers to keep interior sound levels low without that dreaded drone.