PAC Ap4gm61 Amppro 4 Amp Interface Select 20142018 Gmr Vehicles with Most50

Upgrade solution for factory, fixed level, databus-controlled sound systems for 2014-2018 gm(r) vehicles with most50, Reliable pac(r) quality, Time-saving design, prevents need for summing & audio correction devices, Variable volume, fade, balance, bass, mid & treble audio settings, Retains Bluetooth(R), navigation, safety system & all warning chimes audio