Bluetooth 5.2, supports serial port name change (refer to HY5066TWS module user manual), supports one-click TWS pairing, supports AUX insertion into the TWS case without disconnection, power-on auto-connect, default volume is maximum, with volume synchronization TX, RX, GND: TTL serial port configuration 9600, N, 8, 1 At 24V 4A, maximum output power is 2×50W; at 19V 4A, maximum output power is 2×40W; 8–24V power supply, with reverse polarity protection, compatible with laptop power adapters After pairing with TWS, pairing is retained permanently LED indicator: After TWS setup, single board LED stays on and outputs left channel; dual board LED blinks and outputs stereo sound Color: As shown Material: Plastic Function buttons: P/V–: Short press for next track; long press to decrease volume N/V+: Short press for previous track; long press to increase volume PLAY: Short press to play/pause Double-click to toggle ShareMe mode (audio channel switches in loop after TWS setup) Relative sub-unit (left-right-stereo) Press and hold for 3 seconds to reject or re-pair phone (host only) TWS: Short press for one-button TWS pairing Double-click to cycle through EQ modes (9-band EQ) Press and hold for 3 seconds and release to confirm action with prompt tone Press and hold for 6 seconds to clear pairing list and reset EQ to default Slight variations in appearance and printed text may occur between batches; these do not affect functionality Package Contents: 1 × Development Board Note: Color may vary slightly due to lighting and screen settings. Measurement tolerance: ±1–3 cm.