If your performance car audio system is designed for maximum sound quality and maximum control then the four.1i is the car audio processor for you. Designed to be the worlds first professional quality in-dash equalizer the four.1i bodes such features as 13 volt signal capabilities a master volume control and auxiliary inputs for secondary sources. In addition five equalization controls give just the right amount of control for the user. Audiocontrols line of in-dash car processors offer features and functions that allow you to adjust and tweak your performance car audio system from the convenience of the driver seat. Included are features like equalization electronic crossovers master volume control and high voltage line drivers.* 5 band stereo graphic equalizer* para-bass subwoofer equalization* auxiliary input* master volume control* front / rear fader* balanced differential inputs and outputs for maximum noise rejection* high headroom pwm switching power supply* switchable backlight illumination color(green or amber)* 13 volt peak line driverwe have also provided brackets to allow you to mountthe four.1i chassis under the dashboard or glovebox. Thescrew holes on the four.1i chassis also allow for easyinstallation underneath a radio or with a dash kit.