Kit features a one-piece cast back plate with integral breather and mounting brackets for simplified installation and a "state of the art" synthetic media washable air cleaner element that does not require oiling. If you want more torque from your Twin Cam-equipped model, this kit provides a freer breathing capability to pump-up the power of your EFI-equipped motorcycle. This kit includes air cleaner, breather and all required hardware. Street legal when used with stock mufflers. All EFI-equipped models require ECM calibration* (priced separately).