Directly from the RS-R Website:

Sleek in design, this exhaust systems jet-black coating hides the SUS409 stainless steel muffler and piping behind the well known. Each ExMag system is custom tailored for each application. The ExMag muffler can be either a straight through, loop or chambered design.

ExMag's quiet, refined tone coupled with the performance gains found in an aftermarket system creates an exhaust system perfectly designed for the street. By bolting up an ExMag system to your vehicle, you immediately notice the gains in HP, torque and throttle response. It does not take a loud exhaust system to produce the power that you are looking for, and the ExMag is evidence to that.

http://rs-r.com/products/exhaust/exmag.php

...Thats how the fck...