5 Equalization bands, could be adjustable from -12 to + 12db. The Subwoofer frequency is in 30Hz to 120Hz adjustment. Powered at 12 Volts with 6-channel Front, Rear and Subwoofer aux stereo output which enhances your sound experience in the car. That makes sure that your amplifier and speaker receive a powerful but clear signal. Allowed CD and Aux (2 channel) input with gain knob to adjust aux volume, also a CD & AUX input button could switch flexibly to another mode input. Flexible control as your favor, subwoofer volume control, subwoofer frequency control, fader control, each various Hz control. This car equalizer is supplied by DC 12V power. Besides, strong metal chassis with high quality rotary knobs for all controls to enhance your tips feeling. Material: Metal colour: Black Note: The product is a car equalizer, which needs to be used together with the power amplifier (this product does not include the power amplifier and needs to be prepared by yourself) to achieve the output effect! Package Contents: 4 x Car Audio Equalizer Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.