1、Toggle the switch and M key to switch the mode. TX / RX, optical fiber and any mode can be switched arbitrarily in the on state. 2、No need to turn off TX/RX first, just switch between RX/TX without complicated operation, you can switch modes at will. 3、It has a 350mAh rechargeable lithium battery, which can be used without the charging cable. 4、The audio receiver transmitter is easy to use, small and exquisite, easy to carry, and does not take up space. 5、The bluetooth receiver transmiter is made of ABS, durable, wear‑resistant and drop‑resistant. 1 x Host1 x Manual1 x Charging Cable1 x Audio Line1 x Adapter Cable1 x Fiber Optic Cable Item Type: Bluetooth Receiver Transmitter Material: ABSBluetooth Version: 5.0Bluetooth Transmission Distance: Approx. 10m / 32.8ftBluetooth Chip: CSR BC8670Frequency Range: 2.402GHz- 2.480GHzBluetooth Protocol: RX:A2DP AVRCP/TX:A2DPBattery Specification: 350mAh lithium battery (battery included)How to Use:Connect via Bluetooth Pairing: 1. First connect the power cord to the power supply, and then connect to the product. After power on, the Bluetooth audio receiver successfully enters the pairing state. 2. Turn on the Bluetooth function of the mobile phone or other device, search for the device, and click Connect after the search is successful. 3. After the connection is successful, the next time you use it, you only need to press the power button for 3 seconds to turn on the phone and it will automatically connect to the mobile phone or other equipment you used last time.