1. Bluetooth transmission-convert audio signals into Bluetooth signals and provide them to devices that need to use Bluetooth receivers such as: Bluetooth speakers, Bluetooth headsets, Bluetooth boards and other receivers 2. The Bluetooth transmission mode is defined as the master device, and it needs to be paired with devices such as Bluetooth speakers and Bluetooth headsets. After being defined as the Bluetooth transmission mode, this device is a device that sends audio, so the output interface terminal is not output. Only signals can be input. 3. The Bluetooth sending and receiving mode has a memory saving function. After selection, the power-off mode will not change when the power is turned off next time. 4. Pairing connection between Bluetooth and each device: After the Bluetooth device is set to send, adjust the receiving device to the pairing state, and place it at the closest distance for automatic pairing. For pairing, you need to do the following: 1: Turn off the Bluetooth function of the mobile phone around you, turn off other related Bluetooth devices that do not need to be paired (because the product is actively searching for the device, and actively trying to connect the device) 2: Place the two paired devices as close as possible 3: Wait for a period of time, the product will actively find the device and try to connect (remember to turn off other unrelated devices) 4. Bluetooth receiving mode: pairing with the Bluetooth audio signal receiving Bluetooth can be paired with the Bluetooth signal from the mobile phone and other devices, to achieve the decoding of the received Bluetooth signal into stereo left and right channel signals, and the fiber/coaxial output stereo signal can be directly output . Color: black + red Material: PCB Package Include: 1*Audio board Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.