Bluetooth 5.2, supports serial port name change (see HY5066TWS module user manual), supports one-click TWS pairing, supports AUX insertion into the TWS box without disconnection, power on, o call,default volume is maximum, with volume synchronization TX, RX, GND: TTL serial port configuration 9600, N, 8, 1 At 24V4A, the maximum output power is 2x50W;At 19V4A, the maximum output power is 2x40W;8-24V power supply, with reverse connection protection, supports power supply from notebook power adapter After pairing with TWS, it lasts for life LED light: After setting up TWS, the single board is always on and outputs the left channel, and the double board flashes and outputs stereo sound. Colour:As Shown Material:plastic Special button description: P/V-: Short press the next song, long press the volume will decrease. N/V+: Short press to play the previous song, long press to increase the volume. PLAY: Short press to play/pause Double-click to switch shareme (after setting up TWS, the audio channel will be switched online in a loop) Relative sub unit (right-left-stereo) Press and hold for 3S to reject/re-pair the phone (the host is valid) TWS: Short press one-button TWS pairing Double-click to switch EQ (9-band EQ cycle switching) Press and hold for 3S and be sure to release the switch prompt sound Press and hold 6S to clear the pairing list and restore EQ to default Due to different batches, there may be differences in product appearance and printed text, which will not affect use Package Contents: 1 * Development Board