Using Bluetooth 5.1 chip design, the compatibility and stability are stronger. Bluetooth receiving (RX) and Bluetooth transmitting (TX) two in one. Equipped with a high-definition LED digital display, the working status and Bluetooth mode are clearly visible. Built-in decoding chip, heavy bass effect, the device supports treble/bass button adjustment. Upgrade the NFC function, and the mobile phone sensor can be connected with . Bluetooth version: Bluetooth V5.1 Support protocol: A2DP/AVRCP//OPP/GATT/SM 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 interface+6.5 MIC Output: 3.5mm AUX+ Supported formats: MP3/WAV/WMA/APE/FLAC/G729/M4A/ALAC//DTS/MIDI/G726/MTY Working current: Less than 40mA 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 : Type-C 5V/1A Compatible devices: Android, IOS system mobile phones and PADs, active speakers, power amplifiers, and Bluetooth speakers or headphones that support A2DP/protocol. Product size: 98 x 67 x 23.5mm color: Black Material: ABS Package Contents: 1 x Adapter 1 x IR Remote Control 1 x Type-C 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.