BT578V3 version: This is BT578v3. Compared with the old model, the Type-C charging port has been upgraded, and the module has also been upgraded. The power consumption is lower, the transmission distance is longer, and high-speed communication is supported. The packaging has also been upgraded. 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. It replaces the traditional serial port cable for wireless serial port transmission between RS232 serial port device and computer, mobile phone, and tablet. Bluetooth protocol: Bluetooth V3.0 (SPP) + Bluetooth V4.2 (BLE). Transmission power: 5dBm. Receiving sensitivity: -95dBm. Optional serial port baud rate: 2400, 4800, 9600, 19200, 38400, 57600, 115200. Bluetooth BLE serial communication characteristic value: 0000ffe1-0000-1000-8000-00805f9b34fb. Maximum wireless communication distance: 30 meters. Operating temperature: -10°C to 55°C. Typical working current: 8mA. Application scenario: Debug switches, routers, and other network equipment. Connect total station, level meter, equator meter, and other surveying and mapping instruments to read data. Control the optometer and read the data. Data transmission of RS232 equipment such as electronic scale, printer, PLC industrial control, and equipment. Type-C charging interface, built-in large capacity lithium battery, can be fully charged in about one hour, and can be used for about 24 hours when fully charged, or can be directly powered by USB. Material: plastic. Color: as shown. Package Contents: 1 x Adapter Kit (Tag Random). 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 to be slightly different from the real thing. The measurement allowed error is +/- 1-3cm.