Massive Audio UR1 Amplifier Gain Control Knob. Adjustable Gain Amplifier Remote Level Controller for All Current Massive Audio Amplifiers - 0 to 12 dB Sub Amp Gain Control A MUST HAVE | The UR 1 Gain Amplifier Subwoofer Volume Knob allows you to control your Subwoofer output channel from the driver's chair for when you need that quick adjustments without fussing with your Graphic Equalizer or Stereo Volume Controls! | SAVE 10% - Buy ANY 2 OF OUR PRODUCTS using Code MAD10OFF. RATED FIVE STARS | The UR 1 is a great control knob to have and a nice addition to your sound system. With its good build quality, the control knob is very precise, giving you unparalleled level of control on adjusting the bass for different types of music. EASY SETUP | Works great, and it is very easy to mount on your car's console with no hardware to buy. Great for multi-sub setups in cars. Adjust the volume on the fly, and crank it up! HIGH COMPATIBILITY | With the exception of the Drago Series Ampllifiers, the UR 1 Gain Amplifier Remote Knob works with all Massive Audio Amplifier models 2014 and beyond! There's no need for you to change your Remote Subwoofer Volume Knob every time you upgrade your Audio Amplifier! MASSIVE AUDIO QUALITY GUARANTEED | Since 1999, Massive Audio has been an industry leader in high performance audio products. Massive Audio laid its roots in high quality audio reproduction through in-house engineering and a dedication to customers.