Short press for switching among Bluetooth, TF CARD, USB, LINE IN 2 1 Short press to play the previous music under Bluetooth, TF card and USB mode Short press to play previous radio station under FM mode. 3. VOLUME Turning the knob to control the volume up(Turn left) and down(Tum right) 4.4. Short press for music play/pause Long press for radio station automatic searching under FM mode. 5.5. Short press to play the next music under Bluetooth, TF card and USB mode Short press to play next radio station under FM mode. 6. DC 5V Charge Jack for built in battery. When DC 5V cable plugs in, The LED lights up. 7. AUX IN can connect to PC, mp3, Phone, or CD Walkman 8. OFF/ON Speaker power off / Speaker power on 9. USB Port Support USB and can play MP3 and WAV format music in U disk. 10. TF card Port Support TF CARD and can play MP3 and WAV format music in CARD. 11. MIC Plug the microphone into the port enjoy the music 12. Bluetooth Connection -Power on the product or press MODE button to enter into Bluetooth mode. After the device has been paired successfully for the first time it will connect automatically around 10 seconds to the devices which connected before when next time use (Note: Each product could connect to one bluetooth device only. ).