The MVH-S215BT lets you enjoy hands-free calling and audio streaming in the car, courtesy of built-in Bluetooth with an internal mic. Other entertainment options include a front USB input, Aux-In and AM/FM radio. - Receive pristine sound from the MVH-S215BT’s built-in amplifiers with 4 x 50W of pure Mosfet power. For even more power, you can use the RCA pre-out to hook up an amplifier to provide additional power for speakers or subwoofers.