This is a high-speed USB bus adapter module that realizes the function of USB to 8 TTL serial ports. It is used to expand the asynchronous serial port for the computer, or directly upgrade serial port device or MCU to the USB bus. Built-in firmware, emulates the standard serial port, used to upgrade the serial port peripherals, or add additional serial ports through USB. The serial port application under the on the computer is fully compatible without modification. Supports , Linux, Android, macos and other operating systems. Hardware full-duplex serial port, built-in transmit and receive buffer, communication baud rate supports 1200bps-6Mbps. The serial port supports 8 data bits, odd parity, even parity and no parity, and supports 1 or 2 stop bits. Each serial port has a built-in 2048- receive FIF0 and a 1024- transmit . Supports half-duplex, provides 4 TNOWs to indicate the serial port is sending status, which can be used to control RS485 transceiver switch. Supports RS232, RS485, RS422 and other interfaces through external level conversion devices. Indicator light: Red light: Connect USB, 3.3V power indicator light. Emerald green light: The computer driver has been successfully installed, and the emerald green light is on. Normal: It can be used only when both indicators are on. Colour:Black Material:PCB+Plastic Package Contents: 1 x USB to TTL Serial Port Module 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.