Bluetooth(R) Compatible Stream music to your vehicle's FM stereo untethered with full Bluetooth(R) wireless functionality. It converts the Bluetooth(R) wireless signal to FM transmission so you can tune in to your car radio while driving. The frequency is adjustable, displayed on the front of the unit which plugs straight into a 12 or 24V spare cigarette lighter socket. Two USB ports are provided for charging your smartphones or tablets, as well as one of the USB ports being for MP3 and WAV file playback. An onboard microphone also gives you full hands-free call functionality. Features: . Hands-Free Calls Voice Prompt . USB microSD Card Playback . In-Built Microphone . Dual USB Charging Specifications: Display: 0.8?; LED Bluetooth(R) Version: 4.2+EDR Input Voltage: 10-28VDC FM Frequency: 87.5-108.0MHz USB/microSD Capacity: Up to 32GB USB/microSD Audio Format: MP3, WMA USB Output: 2.4A Max (Charging Port) 0.5A Max (Music/Charging Port) 2.9A Total Dimensions: 7 Display Type : LED Display Characters / Digits : 3.5 units Alphanumeric : true Display Colour : Orange Diagonal Screen Size : 0.8in FM Frequency : 87.5MHz, 108.0MHz Bluetooth Version : V4.2 Storage Media Type : USB Flash Memory (Thumbdrive), microSD Maximum Capacity : 32.0GB Length : 70.0mm Width : 43.0mm Height : 38.0mm Required Voltage : 10.0V, 28.0V