NO RADIO NEEDED. The MRB2 is a dash-mounted control pad that allows you to keep your smartphone, iPod or MP3 player tucked away safely and control your audio directly from the control pad using wireless Bluetooth technology. Your phone can automatically pair when the system is powered on, allowing you to play music without having to fumble through apps and on-screen controls. Volume, track forward/back, play, and pause are all a finger's reach away, arranged neatly on the weather-proof control pad.Knowing that not all customers keep their music catalog on their phone, the MRB2 also comes with a 3.5mm auxiliary input that allows playback from all media devices and powered 2.1 amp USB charging port to keep your player going, using your standard device charging cable.Audiophiles will appreciate two pairs of built in 4 volt low level outputs, built-in amplifier turn on wires, and adjustable rear/sub speaker output attenuation: Full/-3db/-6db/OFF functions. The plug and play MRB2 is a scant 2" in diameter, requiring little space, meaning you can place the controller well within arm"s reach on the dash. For those with a little custom flair in their off-road vehicles, SSV also provides a powered dome light switch on the control pad, as well as dimmable blue button back-lighting for easy visibility at night. *For use with speaker pod systems or to upgrade a 3.5mm cable input with volume knob. Requires an external amplifier.