Note: Not all single subwoofer amplifiers with 3.5mm are suitable. Simple and convenient design, easy to install and use. Simply plug the 3.5mm into the subwoofer audio connector and place the other end in your ideal location. With a cable length of up to 5M/16.4FT, you are free to install the bass remote control knob in the front seat or other ideal locations without having to reach the amplifier to adjust the volume. This bass volume knob is designed with pure copper core wire and high quality double insulated PVC protection wire. The regulator is compact and convenient, you can put it anywhere in the front without taking up space. This amplifier bass knob controller is convenient for you to adjust and control the volume level of your car amplifier subwoofer from the front seat or remote position, solving part of the problem of single sound effect, so that you can enjoy the perfect music on your driving trip.