Maxxsonics Mb Quart BT CNTRLR Joystick PREAMPThe MB Quart BT CNTRLR Joystick PREAMP is a Bluetooth controller designed for use with audio systems in boats, ATVs, and other outdoor vehicles. It features a joystick style controller that allows for easy volume and track control, as well as play pause and mute functions. The BT CNTRLR is also equipped with a built in preamp, which can boost the signal from a mobile device or other audio source, improving sound quality and overall performance. The