Transmitter Mode: When the Bluetooth adapter is in transmitter mode, it can be used with a TV and the sound can be transmitted wirelessly to a Bluetooth device (Bluetooth headset) or Bluetooth speaker. Receiver Mode: When our Bluetooth receiver is in RX mode, you can use the Bluetooth reception function of this product to transfer Bluetooth music from your mobile phone, computer and PAD to a device such as a stereo system with an AUX audio input port. Noise Reduction Call: You can use our Bluetooth transmitter and receiver to enable your car call, it is equipped with our new noise reduction technology, you get a clear hands-free call while driving. Please note that when receiving the call, you try to be as close to the MIC as possible. Fully charged for 2 hours, TX mode for 7 hours, RX mode for 12 hours. Power ON/OFF: Long press the multifunction button for 3 seconds, the power indicator of the device lights up, press the multifunction button for 3 seconds, the power off LED of the device will light up. Package Dimensions: 16.9 x 8.4 x 1.7 cm Package includes: 1 x Bluetooth Adapter