Connects to your phone via Bluetooth . Connects to any car audio system via the FM Radio via built-in transmitter or via 3.5mm AUX audio. No installation required solution. Inbuilt advanced microphone pickup Noise cancelling and reduced echo, etc. Includes 3.5mm stereo audio output on the unit for directly connecting to an audio amplifier (Car Stereo 3.5mm input) or use as a mini personal Bluetooth receiver with headphone output. Automatically mutes audio and switches to the call. Updates any car audio system to a modern Bluetooth handsfree compatible unit that plays stereo audio from your phones media player Extra compact. Rechargeable (charger inc.) with Volume, FF/REW, Play/Pause, Answer/Hang-up button control. Very compact: 33x56x14mm