Simplify amplifier installation in your Cadillac, Chevrolet, or GMC vehicle with this Amplifier Integration Interface by PAC. The AP4-GM61 eliminates the need for DSP and summing devices by providing a 6-channel preamp output so you can upgrade your amplifier without modifying the factory radio. This amplifier integration interface retains all audio from factory features and includes plug-and-play connections for easy installation.