A. It is designed with a Bluetooth 5.1 chip, offering relatively strong compatibility and stability. B. It combines Bluetooth reception (RX) and Bluetooth transmission (TX). C. It is equipped with a high - definition LED digital display, making the working status and Bluetooth mode relatively clear at a glance. D. It has a built - in DSP decoding chip, delivering good heavy bass effects. The device supports high - tone/low - tone button adjustment. E. The NFC function is upgraded, allowing the mobile phone sensor to connect to it. F. Bluetooth version: Bluetooth V5.1 G. Supported protocols: A2DP/AVRCP/OPP/GATT H. Operating frequency band: 2.402GHz - 2.480GHz I. Power level: Power level 2 (Class II) J. Sensitivity: - 85dBm, with a bit error rate of less than 0.1%. K. Signal - to - noise ratio: 90dB L. Distortion degree: 0.1% M. Interface types: - Input: 3.5mm AUX + RCA + USB + TF interface + 6.5 MIC - Output: 3.5mm AUX + RCA N. Supported formats: MP3/WAV/WMA/FLAC/G729/M4A/ALAC/DTS/MIDI/G726/MTY O. Operating current: Less than 40mA P. Built - in battery: 3.7V/1200mAh Q. Charging current: Approximately 1000mA (maximum) R. Charging time: Approximately 1.5 hours S. Battery life: Approximately 8 hours, about 8 hours in transmission mode T. Bluetooth range: 30 meters (in an open area) U. Charging method: Type - C 5V/1A V. Compatible devices: Mobile phones and tablets with Android and iOS systems, active speakers, power amplifiers, and Bluetooth speakers or headphones supporting the A2DP protocol. W. Product dimensions: 98 x 67 x 23.5mm X. Color: Black Y. Material: ABS Z. Package contents: - 1 adapter - 1 infrared remote control - 1 Type - C charging cable - 1 red - white RCA cable - 1 AUX audio cable - 1 English instruction manual AA. Only the above package contents are included, and other products are not included. BB. Note: Light reflection and different displays may cause slight differences between the color of the item in the picture and the actual object. A measurement error of plus or minus 1 - 3cm is allowed.