This remote amplifier level control is used to adjust an amplifier's power level, stereo, equalizer or crossover volume form the dashboard or other remote locations. It adds sub-woofer level controls or balances a multiple amplifier installation. Fine tunes the volume of any line level signal you wish to control. Compact housing allows the unit to be mounted virtually anywhere so control is at the user's fingertips. Simple in and out connections, no additional wiring needed. Great for a sub amp volume control. Connect the from the output of this controller to the amplifier, and wire the car stereo output to the input of this unit. Adds a Dash Mounted Sub-Woofer Volume Control. 4 gold plated 's (2 input & 2 output). Level: control knob Frequency: 150Hz - 40Hz Gain: 0db to -12db Dimensions: 68x56x31mm/2.68x2.2x1.22inch colour: as shown Material: plastic+metal Package Contents: 1 x Car Audio Regulator With Screws Only the above package content, other products are not included. Note: Light 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.