Features: Voltage Detection: Equipped with a real-time battery voltage detection chip it monitors the car battery to avoid abnormal voltage issues such as stalling or breaking down. Intelligent Fast Charging: Dual USB ports for simultaneous charging with a current of up to 3.1A so you can use it to charge your phone and tablet. Bluetooth-compatible 5.0 Chip: The Bluetooth-compatible 5.0 chip is compatible with earlier versions and is intended for low-power devices while maintaining high-speed transmission. Power-Off Memory: Automatically connection memory frequency song and volume restart after powered off start play from the first sentence of the song which disconnected due to power broken. After-sales Service: If you have any problem please contact us immediately we will help you solve it as soon as possible. Specifications: Material: ABS Input Current: 3.1A Working Voltage: 12-24V TransmittingFrequency: 87.5-108MHz Bluetooth-compatible Version: 5.0 Notes: Please note that due to the influence of light and screen slight chromatic aberration is acceptable. Please allow slight measurement error due to manual measurement. includes: 1 *Car MP3 Player "