Description: Powerful bluetooth IC, stronger compatibility, support A2DP V1.2 stereo profile. Clip Design: Mini size with clip design, portable, can let you carry them to anywhere you want. 3.5mm Standard Plug: Metal material, detachable two-way 3.5mm male to male audio connector, compact and easy to carry. Built-in Microphone: Support Bluetooth hands-free calling Widely Use: Suitable for mobile TV, MP3, MP4, speaker, Bluetooth headset, laptop, car speaker, and other devices with 3.5mm audio jacks. How to Use: System status: Power on/off: MFB long press for 3 seconds Volume plus: short press VOL+ Volume minus: short press VOL- Switch language: Double click MFB in pairing state Music control: Play/Pause: Short press MFB Previous song: VOL - long press for 2 seconds Next song: VOL+ long press for 2 seconds Telephone control: Answer the call: Short press MFB when calling Refuse to answer the phone: press MFB when calling Redial: Double-click the MFB button, then short press MFB to cancel dialing Led light shows: Boot pairing: red and blue lights alternately flash Connection status: blue light flashes slowly (5 seconds 1 time) Low voltage: red light flashes (0.5 seconds 1 time) Specification: Material: Plastic Bluetooth Version: 5.0 Frequency Range : Profile: A2DP Transmission Range: Up to 10m / 33ft I/O : 3.5mm female plug, Mini USB female port Power Supply: DC 5V Charge Time: About 30 min Working Time: About 4h Size: 1.4*1.5*5.8cm / 0.5*0.6*2.3" (L*W*H) Package Includes: 2 Pieces Bluetooth Receivers 2 Pieces USB Power Cables 2 Pieces 3.5mm Input Jacks 2 Pieces Instruction Manuals