Designed with Bluetooth 5.1 chip for better compatibility and stability. Bluetooth receive (RX), Bluetooth transmit (TX) two in one. Equipped with HD LED digital display, working status and Bluetooth mode are clearly visible. Built-in decoder chip, heavy effect, support three gain adjustable. Upgrade NFC function, cell phone induction connected. Bluetooth version: Bluetooth V5.1 Support protocol: A2DP/AVRCP/HFP/ Working frequency band: 2.402GHz -2.480GHz Power level: Power level 2 (Class II) Sensitivity: -85dBmLess than 0.1%BER Signal-to-noise ratio: ≥90dB Distortion: ≤0.1% Interface Type: Input: 3.5mm AUX++USB+TF card+6.5mm microphone+digital optical fiber+digital coaxial Output: 3.5mm AUX+ Supported formats: MP3/WAV/WMA/APE/FLAC/G729/M4A/ALAC//DTS/MIDI/G726/MTY Built-in battery: 3.7V/1200mAh Charging current: about 1000mA (MAX) Charging time: about 1.5 hours Battery life: RX about 8H, TX about 8H Bluetooth distance: ≤30M (open place) Charging method: Type-C 5V/1A Compatible equipment: mobile phones and tablet computers, active speakers, power amplifiers, desktop computers, mixers, , karaoke machines, etc. Product size: 98 x 67 x 24.2mm color: Black Material: ABS Package Contents: 1 x Adapter 1 x Infrared Remote Control 1 x Charging Cable 1 x Red And White Lotus Cable 1 x Aux Audio Cable 1 x English Manual 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.