This is a Pioneer Reconditioned product, including a 90-day limited warranty. The GM-A6704 4-channel amplifier will greatly improve the sound quality in your vehicle. This amplifier powers your front and rear speakers with 60 watts RMS each, allowing you to hear much more of the little details in your music, especially when you turn your system up to overcome road noise. With this amplifier, you can run your front speakers with the “A” channels and combine the “B” channels to drive a subwoofer. You can also set this versatile amp to 2-channel mode to send 190 watts RMS each to a couple of component speakers or subwoofers. Speaker-level inputs also allow you to add this amplifier to a factory-installed audio source that does not have pre-amplified outputs.