Firstly, the double din radio we sold only supports analog Steering Wheel Control signal input, but some of the car models did not equip with. You can check it from your car dealer.
Secondly, most of cars do not need to install the SWC adapter. You can try to connect SWC leads (Key1 and Key2) from radio with your car SWC wires directly.
If your car only has one SWC wire from car harness, you connect Key1 with the car SWC wire.
Please note that do not miss to connect the car SWC ground wire with Ground wire, or the radio can not recognize the SWC signal from your car.
Thirdly, if your car do not have a analog SWC, or installed a car computer, you can consider to purchase a PAC or Axxess ASWC adapter.
Select a adapter that support your car and transform the SWC signal into analog signal.
Connecting the SWC leads (Key1 and Key2) from radio with the adapter.
Before purchase, please confirm under issues from the dealer:
1. Can this adapter fit your car?
2. Can the adapter fit for the radio without 3.5 mm aux remote port, but only has two analog SWC wires?