DUAL USB CAR CHARGER : 3.1A and 1A,Input 12v/24v offer convenient and charging for you and your friends.USB charging cable is not included.BLUETOOTH FUNCTION : Bluetooth V4.0 ,Transfer Calling / Music / FM / . 5% every hour low power consumption when use bluetooth play music. Mobile navigation,Voice broadcast . Bluetooth connect distances : 5 meters.Fit for most of android and IOS.HANDS FREE FUNCTION : Built-in Microphone,Switch to Hands-free mode automatically from music playing status when receiving calls.Answer/Reject/Hand up/Recall all in one keypad.CAR BATTERY VOLTAGE FUNCTION : Show 3 seconds of Auto voltage when put in the Car cigarette lighter and Speech battery case.Let you always keep battery state of health.Then it will enter the automatic play mode.MUSIC PLAYING FUNCTION : Support Bluetooth Music/ USB Disk/ TF Card / WMA / MP3 format. Listening to music while charging.Power off memory function,From broken song began to play.