BT578V3 version: The is BT578v3. Compared with the old model, the type-c charging port has been upgraded, and the module has also been upgraded.<br> The power consumption is lower, the transmission distance is longer, and high-speed communication is supported. The packaging has also been upgraded.<br> The previous matching charger has been canceled, and you can directly use the mobile phone charger to charge. The red light will go out after full charge!<br> It replaces the traditional serial port cable for wireless serial port transmission between RS232 serial port device and computer, mobile phone and tablet<br> Bluetooth protocol: Bluetooth V3.0 (SPP)+Bluetooth V4.2 (BLE)<br> Transmission power: 5dBm<br> Receiving sensitivity: - 95dBm<br> Optional serial port baud rate: 240048009600192003840057600115200<br> Bluetooth BLE serial communication characteristic value: 0000ffe1-0000-10000-8000-00805f9b34fb<br> Maximum wireless communication distance: 30 meters<br> Operating temperature - 10 - 55<br> Typical working current: 8mA<br> Application scenario: Debug switches, routers and other network equipment<br> Connect total station, level meter, equator meter and other surveying and mapping instruments to read data<br> Control the optometer and read the data<br> Data transmission of RS232 equipment such as electronic scale, printer, PLC industrial control and equipment<br> TYPE-C charging interface, built-in large capacity lithium battery, can be fully in about one hour, and can be used for about 24 hours when fully , or can be directly powered by USB<br> Material: plastic<br> colour: as shown<br> Package Contents:<br> 1 x Adapter Kit(Tag Random)<br> Only the above package content, other products are not included.<br> 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.