This plugs over the original factory 20-pin plug in your vehicle. It would be used if you're replacing your factory radio with aftermarket and don't want to cut up your factory harness like the hack-job shops do. It has wiring pigtails so you can splice it into the aftermarket radio harness of your choice. This was the only 20-pin plug offered by GM, so if you've counted 20 pins on your main plug, this is the one you need. The style of plug this fits over was used in:

• Buick - 1989-1994*
• Cadillac - 1989-1994*
• Chevrolet - 1989*-2002*
• GMC - 1989-2002*
• Oldsmobile - 1989-1994*
• Pontiac - 1989-2002*
• Saturn - 1989-1999*

If your vehicle is equipped with steering wheel controls, this will not accommodate them. But, if you're putting an aftermarket radio in, you would be losing them anyway...

*Not all models had this plug style in all the years listed. Please check your radio before ordering. Some of the 80s and early 90s models had a 21 pin plug. The main parts of the plug (power, ground and speakers) were the same, so you could probably make this work in a 21 pin application too.