RJL (R, R4, RS, T, T4), Fred, Schumit, Eugene, and JUseeTV's PGR . Usage Instructions To operate the 2-Tone exhaust system :

Includes sound attenuation for realistic distance fading, as well as directional and distortion effects based on the camera angle .

Allows drivers to switch between a deep tone and a "crackle" tone using a manual toggle .