Fits Performance and Penland Series Only The Torque Range Modifier (TRM ) is an insert that broadens the available torque range of the machine allowing for better "hook up" in certain conditions. The TRM is not a sound damping device and you should see no difference in speed and power. It cannot be used with a Quiet Core Insert or Spark Arrestor because only one of these can occupy the space in the exhaust at one time.