This device eliminates the O2 sensor on the exhaust of all EFI (injection) models in the title of this listing. WHY USE IT? 1) O2 sensors are manufactured to control the fuel of the motorcycle for economy and pollution regulation reasons. If you remove the O2 sensor the power of the engine increases but if you don't use an eliminator device the FI light will turn on. 2) When you replace the standard exhaust of the bike, the O2 sensor will not work OK with the aftermarket exhaust.That's why most aftermarket exhausts do not have a hole to place the standard motorcycle O2 sensor.The reason for that is the different emmisions flow.If you keep the O2 sensor the bike behaves problematically,increases fuel consumption and loses power.So you need an O2 eliminator to remove the sensor. For more details and installation please click on the Nitro X O2 website link below .