Fangrui Product Details Vol-: Short Press Is To Select The Previous Song; Long Press Is To Decrease The Volume Play/pause: Short Press Is To Switch Between Pause And Play; Long Press Is To Switch Between Usb / Tf / Fm / Line In/bluetooth, Short Press Is To Automatically Search Channels In The Radio Fm State Vol+: Short Press Is To Select The Next Song; Long Press Is To Increase The Volume With Bluetooth Call Function, The Power Supply Voltage Is 5v, And The Current Requirement Is Above 2a Music Format: Mp3 / Wma / Wav / Flac / Ape Lossless Format Music On/off: Power Switch Dc 5v: Charging Interface Switch Indicator Microphone: Call Function Usb: Connect U Disk (maximum Support 32gb) Tf: Connect Tf Memory Card (maximum Support 32gb) Main Control Ic: Ac6826a Bluetooth Ic: Ac6826a Bluetooth 5.0 Power: 2*3w, Connect 2 3w Speakers Radio Fm Frequency: 87.5-107.5 Mhz Support Function Introduction: Support Mp3 / Usb / Tf / Line In / Fm / Bluetooth / Dc 5v Colour: Black Material: Abs Package Contents: 1 X Mp3 Decoder 1 X Cable Only T