This is a multi-function radio in the car, which is easy to install, convenient to operate, powerful, and has voice assistant function, making it safer to make phonecalls/navigation while driving. Features: You can download the APP and control the machine through the mobilephone APP. When connected to the mobilephone BT, long press the volumeknob to wakeup the voice assistant, which makes driving safer. Dual USB interface, which can recharge the mobilephone while reading the USB flash disk. 3 playing modes: memory card, U-disk and AUX. Can be connected to a subwoofer and support an active subwoofer. 5.1 BT, quick and stable connection, low latency. Specifications: FM: 87.5-108.0MHz Output power: 4 * 55W Working voltage: 12-14.4V BT: 5.1 Install size: 178 * 80mm / 7.0 * 3.1in Panel size: 188 * 58mm / 7.4 * 2.3in Host depth: 55mm / 2.2in Audio format: MP3/WMA/WAV/FLAC Remote controller battery: 2 * AAA battery (not included) Package size: 205 * 148 * 76mm / 8.1 * 5.8 * 3.0in Package weight: 370g / 13.1ounce Packing List: 1 * Car Radio 1 * Remote Controller 2 * Cable 2 * Installtion Accessory 1 * User Manual