<p>Features:</p> <p>Just gently rotate the button of the controller. Different frequencies can make the song sound different. It feels very good and is very convenient.</p> <p>Connect the RCA from the output of this controller to the amplifier, and wire the car stereo output to the RCA input of this unit.</p> <p>Great for a sub amp volume control.</p> <p>Used to adjust an amplifier's power level, stereo, equalizer or crossover volume form the dashboard or other remote locations.</p> <p>Adds sub-woofer level controls or balances a multiple amplifier installation.</p> <p>Compact housing allows the unit to be mounted virtually anywhere so control is at the user's fingertips.</p> <p>Fine tunes the volume of any RCA line level signal you to control.</p> <p>Simple in and out connections, no additional wiring needed.</p> <p>Connect the RCA from the output of this Controller to the amplifier, and wire the car stereo output to the RCA input of this unit.</p> <p>Specification:</p> <p>4 RCA: 2 RCA input \u0026 2 RCA output</p> <p>Level control knob</p> <p>Frequency Range: 150Hz - 40Hz</p> <p>Volume Gain Range: 0db to -12db</p> <p>Dimensions: 48x56x41mm\/1.89x2.2x1.61inch</p> <p>material: plastic</p> <p>Color as shown</p> <p>Package Contents:</p> <p>1 x controller</p> <p>Only the above package content, other products are not included.</p> <p>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.</p>