A selective rebuild adds a new air intake system to the original air filter box. The engine becomes more responsive and agile, and the torque increases significantly even at low revs. A Power Commander III usb for the model concerned must be used for tuning purposes. You should keep the original parts, which can be installed again at any time. The Power Commander must be ordered separately. The correct K&N air filter is included. Because the emissions and noise values are altered, this item is not approved for use on public roads.