Function key operation introduction: 1. Switch music or FM: short press the M key 2. Previous/Next: Short press the volume key 3. Volume up/down: long press the volume key To enter FM radio mode: Short press "M key" to enter FM mode. 1. Short press the power button for the first time to automatically search, and the radio station will be automatically saved after the search is completed, please wait patiently. A second short press of the power button can stop the search early. (It will take a few minutes to search all stations. After the search is complete, you can press the volume buttons to switch to your preferred channel). 2. Switch channel: short press the volume key 3. Volume up/down: long press the volume key Note: In FM radio mode, the audio cable will be better when plugged into the charging port as an FM antenna. TWS serial port mode: 1.2 speakers of the same model are turned on at the same time. 2. Immediately after powering on, press and hold the M key of any speaker until the sound is emitted, which means the pairing of the speakers is completed.