The Universal Bass Control Knob for Car Amplifier is a convenient and essential item for controlling the bass levels in your car audio system. With a 4 PIN Extension Cable included, you can easily connect the knob to your amplifier for precise control. Made of durable copper and PVC materials, this freestanding mounting type knob is designed to last. The compact package dimensions make it easy to install and use, providing a user-friendly experience for adjusting your audio settings on the go.