Introduce:The back clip Bluetooth receiver can change your favorite earphones arbitrarily, making your wired earphones and wired devices instantly become wireless Bluetooth devices. Suitable for: suitable for Samsung, suitable for iPhone, suitable for LG, Sony, Motorola, Blackberry, Nokia, Tablet PC, etc.Function description(1) Play music, switch between music up and down,(2) Volume adjustment, Chinese and English voice switching,(3) Incoming call voice reporting function(4) Last number redial(5) Connect two Bluetooth devices at the same time(6) IOS system displays power,(7) Support, car navigation, voice and other softwareSpecification(1) Bluetooth chip and Bluetooth version: 4.1(2) Bluetooth protocol: A2DP AVRCP HFP HSP(3) Battery: 3.7V 60mAh(4) Charging power: 5V/80mAh(5) Sensitivity: 103db +/- 3dB(6) Impedance: 32Mw(7) Transmission distance: 10m without barrier(8) Frequency: 2.4GHZ(9) Talk time: about 2 hours(10) Listening time: about 2.5 hours(11) Standby time: about 80 hours(12) Product weight: 7g(13) Size: 15*14*58mmsystem status (1) Power on and off: long press the power button for 3 seconds (2) Enter pairing: automatically enter the pairing state after booting (3) Volume up and down: short press the volume up button to adjust the volume up, short press the volume down button to adjust the volume down (4) Switch between Chinese and English: double-click the power button in the pairing state (5) Play pause: short press the power button (6) Last song: VolumePress the button for 2 seconds (7) Next song: Press the volume + key for 2 seconds (8) Answer the call: short press the power button (9) Refuse to answer the call: long press the power button when the call comes in (10) Last number replay: double-click the power button; then short press the power button to cancel the dialingLED light display(1) Power on: blue light(2) Shut down: the blue light flashes 3 times and the red light flashes 1 time(3) Pairing: Red and blue lights flash alternately(4) Connection status: the blue light flashes slowly (1 time in 5 seconds)(5) No connection state: the blue light flashes slowly (1 time in 5 seconds)(6) Incoming call: blue light flashes quickly (1 time per second)(7) Low battery: red light flashes quickly (once 1 second)Packing list: 1 USB charging cable, 1 instruction manual, 1 Bluetooth receiver, 1 audio cable.