1. Integrated receiving and mitting (default mitting mode, no pairing password, switchable receiving mode) 2. Call function (receive function) 3. Serial AT control 4. Serial port AT to modify bluetooth name (receiving function) 5. Prompt tone (neutral tone = drip or electronic tone) (receiving function)<br><br>6. Support long the "MODE" key to turn off, short the "MODE" key to turn on, the power consumption is very low All controls support serial AT commands, which are very powerful. TYPE:Bluetooth V5.0 Stereo BK3266 Module color:Blue Material:PCB<br><br>Package Contents: 1 x Module<br><br>Only the above package content, other products are not included. Note: Light reflection 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.