PAC AP4-CH21 Aftermarket Amplifier Interface, new condition. This unit is a perfect addition to any car audio system, allowing for seamless integration of an aftermarket amplifier. The interface is designed for select Chrysler, Dodge, Jeep, and Ram vehicles, and comes with a 1-year warranty for added peace of mind. Crafted in China, this unit is of high quality and comes as a single unit. Take your car audio to the next level with this PAC AP4-CH21 aftermarket amplifier interface.