Today's modern vehicle audio systems are becoming increasingly more sophisticated and complex. PAC (R) Audio engineered this AmpPRO4 Interface to improve your vehicle's audio performance while keeping the original radio's fit and finish. The AP4-CH42 simplifies the installation of upgraded amplifiers in select non-amplified and amplified sound systems with plug-and-play connectors. This amplifier integration interface also allows you to retain important factory features and provides navigation outputs.