1. Bluetooth V5.3 2. Automatically connect the paired Bluetooth devices back. 3. If there is no equipment connection for ten minutes, it be automatically turned off. 4. at full power for 17 hours. 5. answer privately Both RX and TX support simultaneous connection of two Bluetooth devices. The digital tube displays the power. One-button BASS Charging voltage: 5V Charging current: 186mA Working current: 20mA Shutdown current: 47uA Charging time: 2 hours Working time: RX13H/TX17H Battery capacity: 240mAh Bluetooth version: Version 5.3 Bluetooth transmission distance: 10M in a straight line (If there are slight differences in product appearance colors due to different factory batches, it not affect the use.) Color: Gray & Black Material: ABS Package Contents: 1 * adapter 1 * charging cable 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.