Active 2-channel Bass Restoration Processor with Parametric Bass Controls ^^ Preamp and speaker-level inputs (Works with both Factory and Aftermarket Systems) ^^ Provides up to 9.5 Volts of output ^^ Auto turn-on via DC offset or Audio detection ^^ Load selection switch (20, 60, or 20K ohms) to prevent factory radio shut-down ^^ Wired remote bass level control included