2 set USB Bluetooth Adapter 1. In Transmitter mode, turn a non-Bluetooth TV, PC, CD player, for iPod, MP3 / MP4 into Bluetooth transmitter. Receiver mode: perfect for home or vehicle music streaming sound system.2. Simply connect this bluetooth audio receiver to your line-in or auxiliary input on your speakers, pair it to your Bluetooth enabled device, and enjoy the wireless music revolution. 3. Whether you want Bluetooth convenience in your car, through your home-theater system, in your kitchen, bathroom, or bedroom,etc.4. AptX audio codec for a richer and deeper sound experience. Listen to CD-like audio quality at no compromise.5. Simple operation,3.5mm Male to Male Audio Connector or 3.5mm Male to Male Audio Cable to connect the speakers and the receiver. 6. Powerful bluetooth IC,More stronger compatibility.7. Powered by built-in rechargeable li-ion battery via mini USB port , long working time and low consumption. (Mini USB cable included)8. You can play music through your car and answer phone call via the built-in Mic. How to Use:1.Power on/off.Power on: Press and hold the ON/OFF button for 5-7 seconds until you hear a ready for connecting or a sound, it will auto connect the phone which was paired.Power off: Press and hold the ON/OFF button for 4-5 seconds until you hear a "Long be or red led".2.Connect the receiver to your speakersWith 3.5mm Male to Male Audio Connector or 3.5mm Male to Male Audio Cable to connect the speakers and the receiver (if no sound, Please make sure it was inserted completely). Wireless Type: bluetooth Sound Track: Double Content: AUDIO Interface: USB Interface: 3.5mm Bluetooth 4.1 + EDR, transmission distance of 10m; Support Bluetooth hands-free call function; Support Bluetooth A2DP stereo sound Support TF card playback function; Frequency: 2.4GHz; CE, FCC, BQB certification 3.5mm stereo input jack; Sleep mode, energy saving; Power supply: use mini USB cable to charge When your smartphone is paired with the Bluetooth receiver; The p