Aerpro's range of secondary harnesses will plug into any Aerpro Primary Harness including the Steering Wheel Control Adapter type. Simply select the secondary harness based on the head unit brand and its connector. A secondary harness is not required if installing an ISO aftermarket headunit like Philips or Nakamichi. These will plug directly into a Primary Harness or Steering Wheel Control Adapter.
APP8KE4 Kenwood to iso harness
22 pin Kenwood to ISO Harness
DDX, DMX, DNX have on-board SWC interface
KW-V have on-board SWC interface
All others have single wire for external interface