Universal Steering Audio Control Interface When replacing the factory audio system with an aftermarket one, the original steering wheel audio controls become unusable. This product allows you to continue using your steering wheel controls even after replacing your audio/navigation system. It can be installed on most vehicles except for CAN-BUS controlled vehicles from 86y onwards. (Cannot be used with Mitsubishi Diatone navigation systems.) Installation of this product requires a remote control for your audio/navigation system. (The remote control's frequency band must be limited to 38-40kHz.) *CAN-BUS controlled vehicles require a separate SWI-CAN or SWI-CAN2. (Not required if the PAC audio interface has an SWI output.) *Installation requires specialized knowledge, so please consult a professional, such as a specialist shop.